[llvm] [GlobalOpt] Update debug info when changing CC to Fast (PR #144303)

[Maurice Heumann via llvm-commits]

momo5502 wrote:

I'm going to close this. Turns out DW_CC_BORLAND_msfastcall is not at all the same as fastcc. Seems like there is no way to represent fastcc in the PDB, so it doesn't matter right now.

https://github.com/llvm/llvm-project/pull/144303