Implement first kind of polymorphic inlining.

Add HClassTableGet to fetch an ArtMethod from the vtable or imt,
and compare it to the only method the profiling saw.

Change-Id: I76afd3689178f10e3be048aa3ac9a97c6f63295d
diff --git a/runtime/jit/profiling_info.h b/runtime/jit/profiling_info.h
index ddaf02f..ab72373 100644
--- a/runtime/jit/profiling_info.h
+++ b/runtime/jit/profiling_info.h
@@ -68,8 +68,13 @@
     return !classes_[1].IsNull() && classes_[kIndividualCacheSize - 1].IsNull();
   }
 
- private:
+  mirror::Class* GetTypeAt(size_t i) const SHARED_REQUIRES(Locks::mutator_lock_) {
+    return classes_[i].Read();
+  }
+
   static constexpr uint16_t kIndividualCacheSize = 5;
+
+ private:
   uint32_t dex_pc_;
   GcRoot<mirror::Class> classes_[kIndividualCacheSize];