Revert "Revert "Do not update the type of something we already know.""

This reverts commit 63107a804ce17db9789051e1fe310d99d1dae1cb.

bug:22116987
Change-Id: I49a376a5bd2073a69babe122ec0d26e5d2f82461
diff --git a/compiler/optimizing/graph_checker.h b/compiler/optimizing/graph_checker.h
index bafa69d..7c72e23 100644
--- a/compiler/optimizing/graph_checker.h
+++ b/compiler/optimizing/graph_checker.h
@@ -48,6 +48,10 @@
   // Check that the HasBoundsChecks() flag is set for bounds checks.
   void VisitBoundsCheck(HBoundsCheck* check) OVERRIDE;
 
+  // Check that HCheckCast and HInstanceOf have HLoadClass as second input.
+  void VisitCheckCast(HCheckCast* check) OVERRIDE;
+  void VisitInstanceOf(HInstanceOf* check) OVERRIDE;
+
   // Check that the Return and ReturnVoid jump to the exit block.
   void VisitReturn(HReturn* ret) OVERRIDE;
   void VisitReturnVoid(HReturnVoid* ret) OVERRIDE;