Remove support for Javascript warnings in the VM.

runtime/vm/flow_graph_builder.h

Index: runtime/vm/flow_graph_builder.h
diff --git a/runtime/vm/flow_graph_builder.h b/runtime/vm/flow_graph_builder.h
index 6dc14cefc1983cf06842428ecff9c451fbe2d8f2..27062d6c9555f60044eea9fac09f5a7e4ab0da2a 100644
--- a/runtime/vm/flow_graph_builder.h
+++ b/runtime/vm/flow_graph_builder.h
@@ -113,11 +113,6 @@ class FlowGraphBuilder : public ValueObject {
     return ic_data_array_;
   }
 
-  // Return true if a Javascript compatibility warning should be emitted at
-  // runtime for this type test.
-  bool WarnOnJSIntegralNumTypeTest(AstNode* node,
-                                   const AbstractType& type) const;
-
   void Bailout(const char* reason) const;
 
   intptr_t AllocateBlockId() { return ++last_used_block_id_; }