[clang] Fix -Wunused-variable in CGCall.cpp (NFC)

llvm-project/clang/lib/CodeGen/CGCall.cpp:3226:24:
error: unused variable 'StructSize' [-Werror,-Wunused-variable]
        llvm::TypeSize StructSize = CGM.getDataLayout().getTypeAllocSize(STy);
                       ^
llvm-project/clang/lib/CodeGen/CGCall.cpp:3227:24:
error: unused variable 'PtrElementSize' [-Werror,-Wunused-variable]
        llvm::TypeSize PtrElementSize =
                       ^
llvm-project/clang/lib/CodeGen/CGCall.cpp:5313:24:
error: unused variable 'SrcTypeSize' [-Werror,-Wunused-variable]
        llvm::TypeSize SrcTypeSize =
                       ^
llvm-project/clang/lib/CodeGen/CGCall.cpp:5315:24:
error: unused variable 'DstTypeSize' [-Werror,-Wunused-variable]
        llvm::TypeSize DstTypeSize = CGM.getDataLayout().getTypeAllocSize(STy);
                       ^
4 errors generated.

Author: DamonFool

clang/lib/CodeGen/CGCall.cpp

@@ -3223,8 +3223,9 @@ void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI,
           dyn_cast<llvm::StructType>(ArgI.getCoerceToType());
       if (ArgI.isDirect() && !ArgI.getCanBeFlattened() && STy &&
           STy->getNumElements() > 1) {
-        llvm::TypeSize StructSize = CGM.getDataLayout().getTypeAllocSize(STy);
-        llvm::TypeSize PtrElementSize =
+        [[maybe_unused]] llvm::TypeSize StructSize =
+            CGM.getDataLayout().getTypeAllocSize(STy);
+        [[maybe_unused]] llvm::TypeSize PtrElementSize =
             CGM.getDataLayout().getTypeAllocSize(ConvertTypeForMem(Ty));
         if (STy->containsHomogeneousScalableVectorTypes()) {
           assert(StructSize == PtrElementSize &&
@@ -5310,9 +5311,10 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
           dyn_cast<llvm::StructType>(ArgInfo.getCoerceToType());
       if (STy && ArgInfo.isDirect() && !ArgInfo.getCanBeFlattened()) {
         llvm::Type *SrcTy = ConvertTypeForMem(I->Ty);
-        llvm::TypeSize SrcTypeSize =
+        [[maybe_unused]] llvm::TypeSize SrcTypeSize =
             CGM.getDataLayout().getTypeAllocSize(SrcTy);
-        llvm::TypeSize DstTypeSize = CGM.getDataLayout().getTypeAllocSize(STy);
+        [[maybe_unused]] llvm::TypeSize DstTypeSize =
+            CGM.getDataLayout().getTypeAllocSize(STy);
         if (STy->containsHomogeneousScalableVectorTypes()) {
           assert(SrcTypeSize == DstTypeSize &&
                  "Only allow non-fractional movement of structure with "