[clang] [llvm] [WebAssembly] Support acquire-release atomics in CodeGen (PR #184900)

[Heejin Ahn via llvm-commits]

https://github.com/aheejin commented:

These tests currently pass only because we didn't print `seq_cst` in instructions, but comments say Wasm only has seq_cst orderings, which is now not true:
https://github.com/llvm/llvm-project/blob/main/llvm/test/CodeGen/WebAssembly/atomic-fence.ll
https://github.com/llvm/llvm-project/blob/main/llvm/test/CodeGen/WebAssembly/atomic-mem-consistency.ll

https://github.com/llvm/llvm-project/pull/184900