[linux-port] Fix gcc build error (#1800)

lib/Transforms/Scalar/ScalarReplAggregatesHLSL.cpp

@@ -5360,7 +5360,7 @@ Value *SROA_Parameter_HLSL::castArgumentIfRequired(
 }
 
 struct AnnotatedValue {
-  Value *Value;
+  llvm::Value *Value;
   DxilFieldAnnotation Annotation;
 };