Factorize code for common LocationSummary of HInvoke.

This is one step forward, we could factorize more, but
I wanted to get this out of the way first.

Change-Id: I6ae411a737eebaecb64974f47af507ce0cfbae85
diff --git a/compiler/optimizing/code_generator_arm.h b/compiler/optimizing/code_generator_arm.h
index d649cbf..d84f2d3 100644
--- a/compiler/optimizing/code_generator_arm.h
+++ b/compiler/optimizing/code_generator_arm.h
@@ -86,7 +86,8 @@
   virtual ~InvokeDexCallingConventionVisitorARM() {}
 
   Location GetNextLocation(Primitive::Type type) OVERRIDE;
-  Location GetReturnLocation(Primitive::Type type);
+  Location GetReturnLocation(Primitive::Type type) const OVERRIDE;
+  Location GetMethodLocation() const OVERRIDE;
 
  private:
   InvokeDexCallingConvention calling_convention;