This relands changes in https://github.com/llvm/llvm-project/pull/155023
for adding a count of dwo errors and combine all the dwo related stats
into one struct.

The previous PR was reverted in
https://github.com/llvm/llvm-project/pull/156777 as the newly added unit
test `test_dwo_id_mismatch_error_stats` sometimes fails due to
inappropriate use of `glob.glob`.
This change modified the tests created in the former PR to collect and
modify the dwo files by there names instead of using index after
`glob.glob`. This will avoid the possible failure in these tests if the
order of dwo files changes.

[Original PR:
https://github.com/llvm/llvm-project/pull/155023](https://github.com/llvm/llvm-project/pull/155023)

## Testing
Ran unit tests
```
$ ./bin/llvm-lit /data/users/ziyiww/llvm-project/lldb/test/API/commands/statistics/basic/TestStats.py
./bin/llvm-lit /data/users/ziyiww/llvm-project/lldb/test/API/commands/statistics/basic/TestStats.py -v
-- Testing: 1 tests, 1 workers --
PASS: lldb-api :: commands/statistics/basic/TestStats.py (1 of 1)

Testing Time: 388.52s

Total Discovered Tests: 1
  Passed: 1 (100.00%)

$ bin/lldb-dotest -p TestStats.py /data/users/ziyiww/llvm-project/lldb/test/API/commands/statistics/basic/
----------------------------------------------------------------------
Ran 27 tests in 386.302s

OK (skipped=3)
```

Reverts llvm/llvm-project#155023

The PR tests passed, but it failed in the CI. Reverting to give time to
investigate.

## Summary
A new `totalDwoErrorCount` counter is available in statistics when
calling `statistics dump` to track the number of DWO errors.
Additionally, this PR refactors the DWO file statistics by consolidating
the existing functionality for counting loaded and total DWO files
together with the number of DWO errors into a single function that
returns a new DWOStats struct.

1. A new struct, `DWOStats` is created to hold the number of loaded DWO
files, the total number of DWO files and the number of DWO errors.
2. Replaced the previous `GetDwoFileCounts` function for loaded and
total DWO file counts with a single `GetDwoStats()` function returning
the struct `DWOStats`. An override is implemented for `SymbolFileDWARF`
that computes the new DWO error count alongside existing counts in one
pass. If the status of a DWO CU is `Fail`, which means there is error
happened during the loading process, we increment the DWO error counter.
_Note: The newly created function `GetDwoStats` will only be called when
we try to get statistics. Other codepaths will not be affected._
3. In Statistics, we sum up the total number of DWO file loading errors.
This is done by getting `DWOStats` for each symbol file and adding up
the results for each module, then adding to the total count among all
modules.
4. In Statistics, we also updated call sites to use the new combined
function and struct for loaded and total DWO file counts. As it is
possible for one module to have several symbol files, the DWO file
counts in a module's stats are updated to be calculated by adding up the
counts from all symbol files.

## Expected Behavior

- When binaries are compiled with split-dwarf and separate DWO files,
`totalDwoLoadErrorCount` would be the number of dwo files with error
occurs during the loading process, 0 if no error occurs during a loading
process.

- When not using split-dwarf, we expect `totalDwoLoadErrorCount` to be 0
since there no DWO file loading errors would be caused.

- `totalLoadedDwoFileCount` and `totalDwoFileCount` should be correctly
calculated after refactoring and updating.

## Testing
### Manual Testing
We created some files to simulate the possible DWO errors manually and
observed the results generated by statistics dump.
For example, if we delete one of the DWO files generated after
compiling, we would get:
```
(lldb) statistics dump
{
  ...
  "totalDwoLoadErrorCount": 1,
  ...
}
```
We also checked the time cost of `statistics dump` w/o the modification
to make sure no significant time cost increase imported.

### Unit test
Added two unit tests that build with new "dwo_error_foo.cpp" and
"dwo_error_main.cpp" files. For tests with flags -gsplit-dwarf, this
generates 2 DWO files.
In one of the tests, we delete both DWO files and check the result to
see if it reflects the number of DWO files with errors correctly. In
another test we update one of the files but loading the outdated .dwo
file of it, expecting it increments the error count by 1.
To run the test:
```
$ bin/lldb-dotest -p TestStats.py ~/local/llvm-project/lldb/test/API/commands/statistics/basic/ -G "dwo"
----------------------------------------------------------------------
Ran 27 tests in 2.680s

OK (skipped=21)

$ bin/lldb-dotest -p TestStats.py ~/local/llvm-project/lldb/test/API/commands/statistics/basic/
----------------------------------------------------------------------
Ran 27 tests in 370.131s

OK (skipped=3)
```

This relands changes in #144424 for adding a count of DWO files
parsed/loaded and the total number of DWO files.

The previous PR was reverted in #145494 due to the newly added unit
tests failing on Windows and MacOS CIs since these platforms don't
support DWO. This change add an additional
`@add_test_categories(["dwo"])` to the new tests to
[skip](https://github.com/llvm/llvm-project/blob/cd46354dbd10820158edabe14dbd49d9f9010722/lldb/packages/Python/lldbsuite/test/test_categories.py#L56)
these tests on Windows/MacOS.

Original PR: #144424

### Testing
Ran unit tests
```
$ bin/lldb-dotest -p TestStats.py llvm-project/lldb/test/API/commands/statistics/basic/
----------------------------------------------------------------------
Ran 24 tests in 211.391s

OK (skipped=3)
```

Reverts llvm/llvm-project#144424

Caused CI failures.

macOS CI failure was:
```
10:20:36  FAIL: test_dwp_dwo_file_count (TestStats.TestCase)
10:20:36      Test "statistics dump" and the loaded dwo file count.
10:20:36  ----------------------------------------------------------------------
10:20:36  Traceback (most recent call last):
10:20:36    File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/test/API/commands/statistics/basic/TestStats.py", line 639, in test_dwp_dwo_file_count
10:20:36      self.assertEqual(debug_stats["totalDwoFileCount"], 2)
10:20:36  AssertionError: 0 != 2
10:20:36  Config=arm64-/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/lldb-build/bin/clang
10:20:36  ======================================================================
10:20:36  FAIL: test_no_debug_names_eager_loads_dwo_files (TestStats.TestCase)
10:20:36      Test the eager loading behavior of DWO files when debug_names is absent by
10:20:36  ----------------------------------------------------------------------
10:20:36  Traceback (most recent call last):
10:20:36    File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/test/API/commands/statistics/basic/TestStats.py", line 566, in test_no_debug_names_eager_loads_dwo_files
10:20:36      self.assertEqual(debug_stats["totalDwoFileCount"], 2)
10:20:36  AssertionError: 0 != 2
10:20:36  Config=arm64-/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/lldb-build/bin/clang
10:20:36  ======================================================================
10:20:36  FAIL: test_split_dwarf_dwo_file_count (TestStats.TestCase)
10:20:36      Test "statistics dump" and the dwo file count.
10:20:36  ----------------------------------------------------------------------
10:20:36  Traceback (most recent call last):
10:20:36    File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/test/API/commands/statistics/basic/TestStats.py", line 588, in test_split_dwarf_dwo_file_count
10:20:36      self.assertEqual(len(debug_stats["modules"]), 1)
10:20:36  AssertionError: 42 != 1
10:20:36  Config=arm64-/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/lldb-build/bin/clang
```

## Summary
A new `totalLoadedDwoFileCount` and `totalDwoFileCount` counters to
available statisctics when calling "statistics dump".

1. `GetDwoFileCounts ` is created, and returns a pair of ints
representing the number of loaded DWO files and the total number of DWO
files, respectively. An override is implemented for `SymbolFileDWARF`
that loops through each compile unit, and adds to a counter if it's a
DWO unit, and then uses `GetDwoSymbolFile(false)` to check whether the
DWO file was already loaded/parsed.

3. In `Statistics`, use `GetSeparateDebugInfo` to sum up the total
number of loaded/parsed DWO files along with the total number of DWO
files. This is done by checking whether the DWO file was already
successfully `loaded` in the collected DWO data, anding adding to the
`totalLoadedDwoFileCount`, and adding to `totalDwoFileCount` for all CU
units.

## Expected Behavior
- When binaries are compiled with split-dwarf and separate DWO files,
`totalLoadedDwoFileCount` would be the number of loaded DWO files and
`totalDwoFileCount` would be the total count of DWO files.
- When using a DWP file instead of separate DWO files,
`totalLoadedDwoFileCount` would be the number of parsed compile units,
while `totalDwoFileCount` would be the total number of CUs in the DWP
file. This should be similar to the counts we get from loading separate
DWO files rather than only counting whether a single DWP file was
loaded.
- When not using split-dwarf, we expect both `totalDwoFileCount` and
`totalLoadedDwoFileCount` to be 0 since no separate debug info is
loaded.

## Testing
**Manual Testing**
On an internal script that has many DWO files, `statistics dump` was
called before and after a `type lookup` command. The
`totalLoadedDwoFileCount` increased as expected after the `type lookup`.
```
(lldb) statistics dump
{
  ...
  "totalLoadedDwoFileCount": 29,
}
(lldb) type lookup folly::Optional<unsigned int>::Storage
typedef std::conditional<true, folly::Optional<unsigned int>::StorageTriviallyDestructible, folly::Optional<unsigned int>::StorageNonTriviallyDestructible>::type
typedef std::conditional<true, folly::Optional<unsigned int>::StorageTriviallyDestructible, folly::Optional<unsigned int>::StorageNonTriviallyDestructible>::type
...
(lldb) statistics dump
{
  ...
  "totalLoadedDwoFileCount": 2160,
}
```
**Unit test**
Added three unit tests that build with new "third.cpp" and "baz.cpp"
files. For tests with w/ flags `-gsplit-dwarf -gpubnames`, this
generates 2 DWO files. Then, the test incrementally adds breakpoints,
and does a type lookup, and the count should increase for each of these
as new DWO files get loaded to support these.
```
$ bin/lldb-dotest -p TestStats.py ~/llvm-sand/external/llvm-project/lldb/test/API/commands/statistics/basic/
----------------------------------------------------------------------
Ran 20 tests in 211.738s

OK (skipped=3)
```

This commit adds three new commands for managing plugins. The `list`
command will show which plugins are currently registered and their
enabled state. The `enable` and `disable` commands can be used to enable
or disable plugins.

A disabled plugin will not show up to the PluginManager when it iterates
over available plugins of a particular type.

The purpose of these commands is to provide more visibility into
registered plugins and allow users to disable plugins for experimental
perf reasons.

There are a few limitations to the current implementation

1. Only SystemRuntime and InstrumentationRuntime plugins are currently
supported. We can easily extend the existing implementation to support
more types. The scope was limited to these plugins to keep the PR size
manageable.

2. Only "statically" know plugin types are supported (i.e. those managed
by the PluginManager and not from `plugin load`). It is possibly we
could support dynamic plugins as well, but I have not looked into it
yet.

Identical PR to: https://github.com/llvm/llvm-project/pull/134563
Previous PR was approved and landed but broke the build due to bad
merge.
Manually resolve the merge conflict and try to land again.

Co-authored-by: George Hu <georgehuyubo@gmail.com>

This reverts commit 070a4ae2f9bcf6967a7147ed2972f409eaa7d3a6.

Multiple buildbot failures have been reported:
https://github.com/llvm/llvm-project/pull/134563

The build fails with:

  lldb/source/Target/Statistics.cpp:75:39: error: use of undeclared
  identifier 'num_symbols_loaded'