[llvm] [X86] Support EGPR (R16-R31) for APX (PR #67702)

[Phoebe Wang via llvm-commits]

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@@ -158,6 +158,10 @@ X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
     case X86::GR16RegClassID:
     case X86::GR32RegClassID:
     case X86::GR64RegClassID:
+    case X86::GR8_NOREX2RegClassID:
+    case X86::GR16_NOREX2RegClassID:
+    case X86::GR32_NOREX2RegClassID:
+    case X86::GR64_NOREX2RegClassID:
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phoebewang wrote:

Didn't look through one by one, but [here](https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/X86/X86DomainReassignment.cpp#L186-L189) seems have risk since it itrates different instructions.

https://github.com/llvm/llvm-project/pull/67702