[compiler-rt] [libunwind] [llvm] Fix compiling/using libunwind for wasm targets (PR #185770)

[Sam Clegg via cfe-commits]

sbc100 wrote:

Oh I see, `libunwind/src/assembly.h` is only used by `libunwind/src/UnwindRegistersRestore.S` and `libunwind/src/UnwindRegistersSave.S` which themselves should be no-op under wasm and we just don't compile those in emscripten.

I wonder if we should instead widen the `#if !defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__wasm__)` guard on those assembly files to include the entire file?   It seems like they should be 100% no-op in those cases?



https://github.com/llvm/llvm-project/pull/185770