The `llvm-gcc` front-end has been EOL'd at least since 2011 (based on
some `git` archeology). And Clang/LLVM has been removing references to
it ever since.

This patch removes the remaining references to it from LLDB. One benefit
of this is that it will allow us to remove the code checking for
`DW_AT_decl_file_attributes_are_invalid` and
`Supports_DW_AT_APPLE_objc_complete_type`.

This is an ongoing series of commits that are reformatting our Python
code. Reformatting is done with `black` (23.1.0).

If you end up having problems merging this commit because you have made
changes to a python file, the best way to handle that is to run `git
checkout --ours <yourfile>` and then reformat it with black.

RFC: https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style

Differential revision: https://reviews.llvm.org/D151460

Not needed now that we require python 3.

Reviewed By: kastiglione, JDevlieghere

Differential Revision: https://reviews.llvm.org/D131761

Eliminate boilerplate of having each test manually assign to `mydir` by calling
`compute_mydir` in lldbtest.py.

Differential Revision: https://reviews.llvm.org/D128077

Follow to D127355, converting more `assertEquals` to `assertState`.

Differential Revision: https://reviews.llvm.org/D127378

This patch removes the infrastructure to replay the test suite from a
reproducer, as well as the modifications made to the individual tests.

Convert `assertTrue(a == b)` to `assertEqual(a, b)` to produce better failure messages.

These were mostly done via regex search & replace, with some manual fixes.

Differential Revision: https://reviews.llvm.org/D95813

Add the skipIfReproducer decorator to the remaining tests that fail to
replay because the GDB remote packets diverge during replay. This is
*not* expected and should be fixed, but figuring out exactly what caused
the divergence has proven pretty difficult to track down.

I've marked these tests as skipped for now so we can get clean results
and detect new regressions. I have no evidence to believe that these
failures have the same root cause, so I've not assigned them a PR.

Summary:
Around a third of our test sources have LLVM license headers. This patch removes those headers from all test
sources and also fixes any tests that depended on the length of the license header.

The reasons for this are:

* A few tests verify line numbers and will start failing if the number of lines in the LLVM license header changes. Once I landed my patch for valid SourceLocations in debug info we will probably have even more tests that verify line numbers.
* No other LLVM project is putting license headers in its test files to my knowledge.
* They make the test sources much more verbose than they have to be. Several tests have longer license headers than the actual test source.

For the record, the following tests had their line numbers changed to pass with the removal of the license header:
    lldb-api :: functionalities/breakpoint/breakpoint_by_line_and_column/TestBreakpointByLineAndColumn.py
    lldb-shell :: Reproducer/TestGDBRemoteRepro.test
    lldb-shell :: Reproducer/TestMultipleTargets.test
    lldb-shell :: Reproducer/TestReuseDirectory.test
    lldb-shell :: ExecControl/StopHook/stop-hook-threads.test
    lldb-shell :: ExecControl/StopHook/stop-hook.test
    lldb-api :: lang/objc/exceptions/TestObjCExceptions.py

Reviewers: #lldb, espindola, JDevlieghere

Reviewed By: #lldb, JDevlieghere

Subscribers: emaste, aprantl, arphaman, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74839