[llvm] [WebAssembly] Add support for memcmp expansion (PR #148298)

[Luke Lau via llvm-commits]

================
@@ -0,0 +1,144 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s  -O3 -verify-machineinstrs -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -mattr=+simd128 | FileCheck %s
----------------
lukel97 wrote:

I don't think we need -O3/-verify-machineinstrs/+simd128 (just yet)

```suggestion
; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers | FileCheck %s
```

https://github.com/llvm/llvm-project/pull/148298