Make header include guards great again

runtime/vm/simulator_arm.h

Index: runtime/vm/simulator_arm.h
diff --git a/runtime/vm/simulator_arm.h b/runtime/vm/simulator_arm.h
index c163a623c392f1c1eb8f8c2a9674aec36b5bde54..2a505cc2c65e437b45bc93cdbce8bf80ef1b9012 100644
--- a/runtime/vm/simulator_arm.h
+++ b/runtime/vm/simulator_arm.h
@@ -9,10 +9,10 @@
 // which will start execution in the Simulator or forwards to the real entry
 // on a ARM HW platform.
 
-#ifndef VM_SIMULATOR_ARM_H_
-#define VM_SIMULATOR_ARM_H_
+#ifndef RUNTIME_VM_SIMULATOR_ARM_H_
+#define RUNTIME_VM_SIMULATOR_ARM_H_
 
-#ifndef VM_SIMULATOR_H_
+#ifndef RUNTIME_VM_SIMULATOR_H_
 #error Do not include simulator_arm.h directly; use simulator.h.
 #endif
 
@@ -287,4 +287,4 @@ class Simulator {
 
 }  // namespace dart
 
-#endif  // VM_SIMULATOR_ARM_H_
+#endif  // RUNTIME_VM_SIMULATOR_ARM_H_