Handle "Mov" which is mov, movss, movsd, and used for nacl.read.tp.

src/IceTargetLoweringX8632.cpp

Index: src/IceTargetLoweringX8632.cpp
diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index 4e04186d47cfa98568ca83d878fefd6c8f261506..ab021c6ef6fd9b143df869802c02141340ed89f1 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -1058,6 +1058,7 @@ Operand *TargetX8632::hiOperand(Operand *Operand) {
       Offset = Ctx->getConstantInt32(IceType_i32, 4 + IntOffset->getValue());
     } else if (ConstantRelocatable *SymOffset =
                    llvm::dyn_cast<ConstantRelocatable>(Offset)) {
+      assert(!Utils::WouldOverflowAdd(SymOffset->getOffset(), 4));
       Offset = Ctx->getConstantSym(IceType_i32, 4 + SymOffset->getOffset(),
                                    SymOffset->getName());
     }