Fix terrible interaction with code flushing.

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index ef21f1f46f9e65ff227bdefb703fe4132101c59e..52451c6bbd046c008765f545925562e591766e8b 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -705,7 +705,10 @@ MUST_USE_RESULT static MaybeHandle<Code> GetCodeFromOptimizedCodeMap(
       }
       FixedArray* literals = shared->GetLiteralsFromOptimizedCodeMap(index);
       if (literals != NULL) function->set_literals(literals);
-      return Handle<Code>(shared->GetCodeFromOptimizedCodeMap(index));
+      Code* code = shared->GetCodeFromOptimizedCodeMap(index);
+      DCHECK(!code->marked_for_deoptimization());
+      DCHECK(function->shared()->is_compiled());
+      return Handle<Code>(code);
     }
   }
   return MaybeHandle<Code>();