Avoid Attr.h includes, CodeGen edition
This saves around 20 includes of Attr.h. Not much.
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 7b5d691..890019a 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -20,6 +20,7 @@
#include "PatternInit.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
+#include "clang/AST/Attr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/OSLog.h"
#include "clang/Basic/TargetBuiltins.h"