Revert "Optimize IMT"

Bug: 29188168 (for initial CL)
Bug: 29778499 (reason for revert)

This reverts commit badee9820fcf5dca5f8c46c3215ae1779ee7736e.

Change-Id: I32b8463122c3521e233c34ca95c96a5078e88848
diff --git a/runtime/entrypoints/entrypoint_utils-inl.h b/runtime/entrypoints/entrypoint_utils-inl.h
index 916ca29..fc62573 100644
--- a/runtime/entrypoints/entrypoint_utils-inl.h
+++ b/runtime/entrypoints/entrypoint_utils-inl.h
@@ -559,10 +559,9 @@
       }
     }
     case kInterface: {
-      uint32_t imt_index = resolved_method->GetDexMethodIndex() % ImTable::kSize;
-      size_t pointer_size = class_linker->GetImagePointerSize();
-      ArtMethod* imt_method = (*this_object)->GetClass()->GetImt(pointer_size)->
-          Get(imt_index, pointer_size);
+      uint32_t imt_index = resolved_method->GetDexMethodIndex() % mirror::Class::kImtSize;
+      ArtMethod* imt_method = (*this_object)->GetClass()->GetEmbeddedImTableEntry(
+          imt_index, class_linker->GetImagePointerSize());
       if (!imt_method->IsRuntimeMethod()) {
         if (kIsDebugBuild) {
           mirror::Class* klass = (*this_object)->GetClass();