We can omit the call to Target::HasLoadedSections as
Address::HasLoadedSections already "does the right thing" and returns
LLDB_INVALID_ADDRESS if no sections are loaded.

This was removed in https://github.com/llvm/llvm-project/pull/135343 in
favour of making it a format variable, which we do here. This follows
the precedent of the `[opt]` and `[artificial]` markers.

Before:
```
 thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.2
 * frame #0: 0x000000010000037c a.out`inlined1() at inline.cpp:4:3
   frame #1: 0x000000010000037c a.out`regular() at inline.cpp:6:17
   frame #2: 0x00000001000003b8 a.out`inlined2() at inline.cpp:7:43
   frame #3: 0x00000001000003b4 a.out`main at inline.cpp:10:3
   frame #4: 0x0000000186345be4 dyld`start + 7040
```

After (note the `[inlined]` markers):
```
thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.2
* frame #0: 0x000000010000037c a.out`inlined1() at inline.cpp:4:3 [inlined]
  frame #1: 0x000000010000037c a.out`regular() at inline.cpp:6:17
  frame #2: 0x00000001000003b8 a.out`inlined2() at inline.cpp:7:43 [inlined]
  frame #3: 0x00000001000003b4 a.out`main at inline.cpp:10:3
  frame #4: 0x0000000186345be4 dyld`start + 7040
```

rdar://152642178

This fixes a data race between the main thread and the default event
handler thread. The statusline format option value was protected by a
mutex, but it was returned as a pointer, allowing one thread to access
it while another was modifying it.

Avoid the data race by returning format values by value instead of by
pointer.

This PR is a subset of the commits made in
https://github.com/swiftlang/llvm-project/pull/10710.

The most notable change is the addition of `PrefixRange` and
`SuffixRange` which are a catch-all to track anything after or before a
function's demangled name. In the case of Swift, this allows to add
support for name highlighting without having to track the range of the
scope and specifiers of a function (this will come in another PR).

This PR implements support for specifying multiple alternatives for
scope format entries. Scopes are used to enclose things that should only
be printed when everything in the scope resolves.

For example, the following scope only resolves if both
`${line.file.basename}` and `${line.number}` resolve. `

```
{ at ${line.file.basename}:${line.number}}
```

However, the current implementation doesn't let you specify what to
print when they don't resolve. This PR adds support for specifying
multiple alternative scopes, which are evaluated left-to-right.

For example:

```
{ at ${line.file.basename}:${line.number}| in ${function.name}| <unknown location>}
```

This will resolve to:

- ` at ${line.file.basename}:${line.number}` if the corresponding
variables resolve.
- Otherwise, this resolves to ` in ${function.name}` if
`${function.name}` resolves.
- Otherwise, this resolves to ` <unknown location>` which always
resolves.

This PR makes the `|` character a special character within a scope, but
allows it to be escaped.

I ended up with this approach because it fit quite nicely in the
existing architecture of the format entries and by limiting the
functionality to scopes, it sidesteps some complexity, like dealing with
recursion.

This reverts commit da7099290cea7d11b83da01adda8afeb3bcd5362.

Same as the original PR. The failing test-case was resolved in https://github.com/llvm/llvm-project/pull/137763

This patch adds another frame-format variable (currently only
implemented in the CPlusPlus language plugin) that represents the
"suffix" of a function. The name is derived from the `DotSuffix` node of
LLVM's Itanium demangler.

For a function name such as `int foo() (.cold)`, the suffix would be
`(.cold)`.

Reverts llvm/llvm-project#137408

This change broke `lldb/test/Shell/Unwind/split-machine-functions.test`.

The test binary has a symbol named `_Z3foov.cold` and the test expects
the backtrace to print the name of the cold part of the function like
this:

```
# SPLIT: frame #1: {{.*}}`foo() (.cold) +
```
but now it gets

```
frame #1: 0x000055555555514f split-machine-functions.test.tmp`foo() + 12
```

This patch changes the progress count formatting show thousands
separator making it easier to read big numbers.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>