Revert "Revert "Refactor GetIMTIndex""

Originally reverted in order to revert
https://android-review.googlesource.com/#/c/244190/
but can now be merged again.

This reverts commit d4ceecc85a5aab2ec23ea1bd010692ba8c8aaa0c.

Test: m test-art-host

Change-Id: Id9205f2b77a378fc0f06088e78c66e81a49f712d
diff --git a/compiler/optimizing/code_generator_mips64.cc b/compiler/optimizing/code_generator_mips64.cc
index aa1ba84..4e21470 100644
--- a/compiler/optimizing/code_generator_mips64.cc
+++ b/compiler/optimizing/code_generator_mips64.cc
@@ -2951,7 +2951,7 @@
   __ LoadFromOffset(kLoadDoubleword, temp, temp,
       mirror::Class::ImtPtrOffset(kMips64PointerSize).Uint32Value());
   uint32_t method_offset = static_cast<uint32_t>(ImTable::OffsetOfElement(
-      invoke->GetImtIndex() % ImTable::kSize, kMips64PointerSize));
+      invoke->GetImtIndex(), kMips64PointerSize));
   // temp = temp->GetImtEntryAt(method_offset);
   __ LoadFromOffset(kLoadDoubleword, temp, temp, method_offset);
   // T9 = temp->GetEntryPoint();