[llvm] [memprof] Add YAML-based deserialization for MemProf profile (PR #117829)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

@kazutakahirata I'm seeing MSVC build warnings due to e98396f4846bfcaabe2c2ee568aab4b78655f307:
```
E:\llvm\llvm-project\llvm\lib\ProfileData\MemProfReader.cpp(56): error C2220: the following warning is treated as an error
E:\llvm\llvm-project\llvm\lib\ProfileData\MemProfReader.cpp(56): warning C4189: '<structured binding>': local variable is initialized but not referenced
```

https://github.com/llvm/llvm-project/pull/117829