[llvm] [X86][MC] Added support for -msse2avx option in llvm-mc (PR #96860)

[Fangrui Song via llvm-commits]

================
@@ -108,6 +109,10 @@ llvm::mc::RegisterMCTargetOptionsFlags::RegisterMCTargetOptionsFlags() {
       cl::desc("Emit internal instruction representation to assembly file"));
   MCBINDOPT(ShowMCInst);
 
+  static cl::opt<bool> SSE2AVX(
+      "msse2avx", cl::desc("Convert SSE Instructions to AVX Instructions"));
----------------
MaskRay wrote:

llvm-mc is an internal tool and its option names are different from clang/gas.... Unlike Clang/GCC, which can define `-m*` options for a specific target, the option names from different targets have a single namespace. It's good to make the target-specific nature clearer.

https://github.com/llvm/llvm-project/pull/96860