[llvm] [AMDGPU] Register allocation anti-hints to reduce MFMA hazard NOPs (PR #156943)

[Quentin Colombet via llvm-commits]

================
@@ -859,6 +866,56 @@ class MachineRegisterInfo {
     return RegAllocHints.inBounds(VReg) ? &RegAllocHints[VReg] : nullptr;
   }
 
+  /// addRegAllocAntiHint - Add a register allocation anti-hint for the
----------------
qcolombet wrote:

Nit: Here and every added method: Don't repeat the method name in the comment.

https://github.com/llvm/llvm-project/pull/156943