Make header include guards great again

runtime/vm/ast.h

Index: runtime/vm/ast.h
diff --git a/runtime/vm/ast.h b/runtime/vm/ast.h
index cd25dc70a85299068fa06bb5b8bd990b3b00cc60..8fa533b9eae767d5790e1bddcd73fed9eb79c068 100644
--- a/runtime/vm/ast.h
+++ b/runtime/vm/ast.h
@@ -2,8 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#ifndef VM_AST_H_
-#define VM_AST_H_
+#ifndef RUNTIME_VM_AST_H_
+#define RUNTIME_VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
@@ -2026,4 +2026,4 @@ class InlinedFinallyNode : public AstNode {
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
-#endif  // VM_AST_H_
+#endif  // RUNTIME_VM_AST_H_