[compiler-rt] [msan] Unwind stack before fatal reports (PR #77168)

[Fangrui Song via llvm-commits]

MaskRay wrote:

In some functions there is a parameter `*stack` and a variable `stack` in a scope. I wonder whether the variable name for `FATAL` should be changed to reduce confusion...

https://github.com/llvm/llvm-project/pull/77168