Normalize the include guard style.

An leading underscore followed by a capital letter is a reserved
name space in C and C++.

This change also moves any #include directives within the include
guard in some of the compiler/codegen/arm header files.

Change-Id: I9715e2c5301699d31886e61d0fe6e29483555a2a
diff --git a/vm/compiler/CompilerInternals.h b/vm/compiler/CompilerInternals.h
index 9a30b34..d635286 100644
--- a/vm/compiler/CompilerInternals.h
+++ b/vm/compiler/CompilerInternals.h
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef _DALVIK_VM_COMPILER_INTERNAL
-#define _DALVIK_VM_COMPILER_INTERNAL
+#ifndef DALVIK_VM_COMPILER_INTERNAL_H_
+#define DALVIK_VM_COMPILER_INTERNAL_H_
 
 #include "Dalvik.h"
 #include "CompilerUtility.h"
 #include "codegen/CompilerCodegen.h"
 #include "interp/Jit.h"
 
-#endif /* _DALVIK_VM_COMPILER_INTERNAL */
+#endif  // DALVIK_VM_COMPILER_INTERNAL_H_