Use class def index from java.lang.Class.

Bug: 10244719
Depends on:
https://googleplex-android-review.git.corp.google.com/362363
This removes the computation of the dex file index, when necessary this is
computed by searching the dex file. Its only necessary in
dalvik.system.DexFile.defineClassNative and DexFile::FindInClassPath, the
latter not showing up significantly in profiling with this change.

Change-Id: I20c73a3b17d86286428ab0fd21bc13f51f36c85c
diff --git a/runtime/entrypoints/quick/quick_invoke_entrypoints.cc b/runtime/entrypoints/quick/quick_invoke_entrypoints.cc
index 1d8022f..07c1c01 100644
--- a/runtime/entrypoints/quick/quick_invoke_entrypoints.cc
+++ b/runtime/entrypoints/quick/quick_invoke_entrypoints.cc
@@ -32,7 +32,7 @@
                                                  Thread* self, mirror::ArtMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   mirror::ArtMethod* method;
-  if (LIKELY(interface_method->GetDexMethodIndex() != DexFile::kDexNoIndex16)) {
+  if (LIKELY(interface_method->GetDexMethodIndex() != DexFile::kDexNoIndex)) {
     method = this_object->GetClass()->FindVirtualMethodForInterface(interface_method);
     if (UNLIKELY(method == NULL)) {
       FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsAndArgs);