[CGExprScalar] Use getSigned() for signed value

clang/lib/CodeGen/CGExprScalar.cpp

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 9b6497f..96274cf 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -3435,7 +3435,7 @@
     CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType());
     if (!isInc) size = -size;
     llvm::Value *sizeValue =
-      llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity());
+        llvm::ConstantInt::getSigned(CGF.SizeTy, size.getQuantity());
 
     if (CGF.getLangOpts().PointerOverflowDefined)
       value = Builder.CreateGEP(CGF.Int8Ty, value, sizeValue, "incdec.objptr");