More #include cleaning
 - Drop Expr.h,RecordLayout.h from ASTContext.h (for DeclBase.h and
   SourceLocation.h)
 - Move ASTContext constructor into implementation

llvm-svn: 54627
diff --git a/clang/lib/AST/Builtins.cpp b/clang/lib/AST/Builtins.cpp
index e2bf5ca..8249c41 100644
--- a/clang/lib/AST/Builtins.cpp
+++ b/clang/lib/AST/Builtins.cpp
@@ -13,6 +13,7 @@
 
 #include "clang/AST/Builtins.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/TargetInfo.h"
 using namespace clang;