Subzero: Improve x86-32's implementation of getGprForType().

src/IceTargetLoweringX86BaseImpl.h

Index: src/IceTargetLoweringX86BaseImpl.h
diff --git a/src/IceTargetLoweringX86BaseImpl.h b/src/IceTargetLoweringX86BaseImpl.h
index d2a353021982f565e3ef17e83b252e9e34882369..ad0602a3eab67215dc209f96083aad17ee807e08 100644
--- a/src/IceTargetLoweringX86BaseImpl.h
+++ b/src/IceTargetLoweringX86BaseImpl.h
@@ -2569,9 +2569,7 @@ void TargetX86Base<TraitsType>::lowerCall(const InstCall *Instr) {
       break;
     case IceType_i64:
       if (Traits::Is64Bit) {
-        ReturnReg = makeReg(
-            IceType_i64,
-            Traits::getGprForType(IceType_i64, Traits::RegisterSet::Reg_eax));
+        ReturnReg = makeReg(IceType_i64, Traits::getRaxOrDie());
       } else {
         ReturnReg = makeReg(IceType_i32, Traits::RegisterSet::Reg_eax);
         ReturnRegHi = makeReg(IceType_i32, Traits::RegisterSet::Reg_edx);