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_mips.cc b/compiler/optimizing/code_generator_mips.cc
index 2b71da0..f50d016 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -3791,7 +3791,7 @@
   __ LoadFromOffset(kLoadWord, temp, temp,
       mirror::Class::ImtPtrOffset(kMipsPointerSize).Uint32Value());
   uint32_t method_offset = static_cast<uint32_t>(ImTable::OffsetOfElement(
-      invoke->GetImtIndex() % ImTable::kSize, kMipsPointerSize));
+      invoke->GetImtIndex(), kMipsPointerSize));
   // temp = temp->GetImtEntryAt(method_offset);
   __ LoadFromOffset(kLoadWord, temp, temp, method_offset);
   // T9 = temp->GetEntryPoint();
@@ -5389,7 +5389,7 @@
                       method_offset);
   } else {
     uint32_t method_offset = static_cast<uint32_t>(ImTable::OffsetOfElement(
-        instruction->GetIndex() % ImTable::kSize, kMipsPointerSize));
+        instruction->GetIndex(), kMipsPointerSize));
     __ LoadFromOffset(kLoadWord,
                       locations->Out().AsRegister<Register>(),
                       locations->InAt(0).AsRegister<Register>(),