Add support for registering classpath classes status.

By doing class unloading after each dex file compilation, we are loosing
away verification done on classpath classes.

This change introduces a new table for keeping around class status of
classpath classes.

Multidex quickening compilation improved by ~5% by not re-verifying classpath
classes.

Bug: 63467744

test: test.py
test: golem successfully compiles FB
Change-Id: I629c0a7d86519bbc516f5e59f7cd92ca6ca842eb
diff --git a/runtime/compiler_callbacks.h b/runtime/compiler_callbacks.h
index 9b22714..9041df9 100644
--- a/runtime/compiler_callbacks.h
+++ b/runtime/compiler_callbacks.h
@@ -65,6 +65,9 @@
     return mode_ == CallbackMode::kCompileBootImage;
   }
 
+  virtual void UpdateClassState(ClassReference ref ATTRIBUTE_UNUSED,
+                                ClassStatus state ATTRIBUTE_UNUSED) {}
+
  protected:
   explicit CompilerCallbacks(CallbackMode mode) : mode_(mode) { }