When you are trying for instance to set a breakpoint on a function by
name, but the SBFunction or SBSymbol are returning demangled names with
argument lists, that match can be tedious to do. Internally, the base
name of a symbol is something we handle all the time, so it's reasonable
that there should be a way to get that info from the API as well.

rdar://159318791

This way all the tracking is self-contained in `TrackingOutputBuffer`
and we can test the `SuffixRange` properly.

This way we make sure that the logic to reconstruct demangled names in
the tests is the same as the logic when reconstructing the actual
frame-format variable.

`DemangledNameInfo::SuffixRange` is currently the only one which we
can't test in the same way until we set it from inside the
`TrackingOutputBuffer`. I added TODOs to track this.

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).

Uses the `TrackingOutputBuffer` to populate the new member `Mangled::m_demangled_info`.

`m_demangled_info` is lazily popluated by `GetDemangledInfo`. To ensure `m_demangled` and `m_demangled_info` are in-sync we clear `m_demangled_info` anytime `m_demangled` is set/cleared.

https://github.com/llvm/llvm-project/pull/131836

Add version of GetDemangledName that will force re-demangling. This is required because LLDB will SetDemangledName without going through the demangler. So we need a way to force demangling to set the m_demangled_info member when we need it.

https://github.com/llvm/llvm-project/pull/131836

The original PR is #132274.

Co-authored-by: @bulbazord Alex Langford

Reverts llvm/llvm-project#132274

Broke a test on LLDB Widows on Arm:
https://lab.llvm.org/buildbot/#/builders/141/builds/7726
```
FAIL: test_dwarf (lldbsuite.test.lldbtest.TestExternCSymbols.test_dwarf)
<...>
    self.assertTrue(self.res.Succeeded(), msg + output)

AssertionError: False is not true : Command 'expression -- foo()' did not return successfully

Error output:

error: Couldn't look up symbols:

  int foo(void)

Hint: The expression tried to call a function that is not present in the target, perhaps because it was optimized out by the compiler.
```