runtime: Minor cleanup and extra comments around interpreter

Change-Id: I24c0b261de8cf737babd9d01bf679482d48c8bc9
diff --git a/compiler/dex/verified_method.h b/compiler/dex/verified_method.h
index 242e3df..07f9a9b 100644
--- a/compiler/dex/verified_method.h
+++ b/compiler/dex/verified_method.h
@@ -120,7 +120,7 @@
   DequickenMap dequicken_map_;
   SafeCastSet safe_cast_set_;
 
-  bool has_verification_failures_;
+  bool has_verification_failures_ = false;
 
   // Copy of mapping generated by verifier of dex PCs of string init invocations
   // to the set of other registers that the receiver has been copied into.