[compiler-rt] [ASan] Recognize WASI platform in sanitizer_platform.h (PR #139017)

[Yuta Saito via llvm-commits]

kateinoigakukun wrote:

While this is a very platform-scoped change, I'd like to have explicit approval before landing. Would someone give approval on this?

https://github.com/llvm/llvm-project/pull/139017