Subzero: Fix x86 lowering for shift-by-relocatable-constant.

src/IceTargetLoweringX86BaseImpl.h

Index: src/IceTargetLoweringX86BaseImpl.h
diff --git a/src/IceTargetLoweringX86BaseImpl.h b/src/IceTargetLoweringX86BaseImpl.h
index 85c8c712848fea00c1e1c351550c835812d018dc..f275c3aec6d14a7658e0fe6e5af8b503f6ccdcf3 100644
--- a/src/IceTargetLoweringX86BaseImpl.h
+++ b/src/IceTargetLoweringX86BaseImpl.h
@@ -1835,21 +1835,21 @@ void TargetX86Base<Machine>::lowerArithmetic(const InstArithmetic *Inst) {
     break;
   case InstArithmetic::Shl:
     _mov(T, Src0);
-    if (!llvm::isa<Constant>(Src1))
+    if (!llvm::isa<ConstantInteger32>(Src1))
       Src1 = legalizeToReg(Src1, Traits::RegisterSet::Reg_ecx);
     _shl(T, Src1);
     _mov(Dest, T);
     break;
   case InstArithmetic::Lshr:
     _mov(T, Src0);
-    if (!llvm::isa<Constant>(Src1))
+    if (!llvm::isa<ConstantInteger32>(Src1))
       Src1 = legalizeToReg(Src1, Traits::RegisterSet::Reg_ecx);
     _shr(T, Src1);
     _mov(Dest, T);
     break;
   case InstArithmetic::Ashr:
     _mov(T, Src0);
-    if (!llvm::isa<Constant>(Src1))
+    if (!llvm::isa<ConstantInteger32>(Src1))
       Src1 = legalizeToReg(Src1, Traits::RegisterSet::Reg_ecx);
     _sar(T, Src1);
     _mov(Dest, T);