[llvm] [CodeView] Match MSVC implicit this records for Visual Studio (PR #214289)

[via llvm-commits]

GkvJwa wrote:

> Also, it seems unlikely to me that the MSVC debugger really can't handle DEFRANGE for "this". What does MSVC do if a function is inlined?

The key here is to change S_LOCAL to S_REGREL32 so that the debugger can parse it correctly.

The issue with S_DEFRANGE is that the information generated by MSVC links to specific registers. Similar to adding `S_DEFRANGE REGISTER + Register = RCX`, this allows `RCX` to be directly labeled as `[this]` during disassembly. This can be added later in a separate PR.


https://github.com/llvm/llvm-project/pull/214289