[clang] [compiler-rt] [lld] [llvm] [Coverage][WebAssembly] Add initial support for WebAssembly/WASI (PR #111332)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

perhaps the `flock` cmake check doesn't work on windows for some reason? maybe wrong include?

https://github.com/llvm/llvm-project/pull/111332