code review feedback - add header ifdef and comment

Author: hekota

clang/lib/Sema/HLSLBuiltinTypeDeclBuilder.cpp

@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 //
+// Helper classes for creating HLSL builtin class types. Used by external HLSL
+// sema source.
 //
 //===----------------------------------------------------------------------===//
 

clang/lib/Sema/HLSLBuiltinTypeDeclBuilder.h

@@ -6,9 +6,14 @@
 //
 //===----------------------------------------------------------------------===//
 //
+// Helper classes for creating HLSL builtin class types. Used by external HLSL
+// sema source.
 //
 //===----------------------------------------------------------------------===//
 
+#ifndef LLVM_CLANG_SEMA_HLSLBUILTINTYPEDECLBUILDER_H
+#define LLVM_CLANG_SEMA_HLSLBUILTINTYPEDECLBUILDER_H
+
 #include "clang/AST/Type.h"
 #include "clang/Sema/Sema.h"
 #include "llvm/ADT/StringMap.h"
@@ -94,3 +99,5 @@ class BuiltinTypeDeclBuilder {
 } // namespace hlsl
 
 } // namespace clang
+
+#endif // LLVM_CLANG_SEMA_HLSLBUILTINTYPEDECLBUILDER_H