Refactor GetIMTIndex

This allows us to more easily maintain and experiment with
interface method table indexing and hashing.

Change-Id: I719920fae7490dcedcda7c1c36db225c2b8b16df
diff --git a/runtime/entrypoints/entrypoint_utils-inl.h b/runtime/entrypoints/entrypoint_utils-inl.h
index 916ca29..db3f88f 100644
--- a/runtime/entrypoints/entrypoint_utils-inl.h
+++ b/runtime/entrypoints/entrypoint_utils-inl.h
@@ -19,7 +19,7 @@
 
 #include "entrypoint_utils.h"
 
-#include "art_method.h"
+#include "art_method-inl.h"
 #include "class_linker-inl.h"
 #include "common_throws.h"
 #include "dex_file.h"
@@ -559,7 +559,7 @@
       }
     }
     case kInterface: {
-      uint32_t imt_index = resolved_method->GetDexMethodIndex() % ImTable::kSize;
+      uint32_t imt_index = resolved_method->GetImtIndex();
       size_t pointer_size = class_linker->GetImagePointerSize();
       ArtMethod* imt_method = (*this_object)->GetClass()->GetImt(pointer_size)->
           Get(imt_index, pointer_size);