[compiler-rt] [libcxx] [libcxxabi] [libunwind] [libunwind][libcxx][libcxxabi][compiler-rt-builtins] Fix Exception Handling build for wasm (PR #79667)

[Alexander Richardson via cfe-commits]

https://github.com/arichardson requested changes to this pull request.

There are tons of unrelated changes that make this really hard to review. Please do the formatting part of the changes separately and address the outstanding comments.

https://github.com/llvm/llvm-project/pull/79667