Partially revert r26703 and omit regular code generation for implicit accessors.

runtime/vm/flow_graph_compiler.h

Index: runtime/vm/flow_graph_compiler.h
diff --git a/runtime/vm/flow_graph_compiler.h b/runtime/vm/flow_graph_compiler.h
index 3151009d9b2853b204811f222ed7276ca05177c2..bebb3b91ae533b7976974e367959be9d74945e62 100644
--- a/runtime/vm/flow_graph_compiler.h
+++ b/runtime/vm/flow_graph_compiler.h
@@ -328,7 +328,10 @@ class FlowGraphCompiler : public ValueObject {
   // Bail out of the flow graph compiler. Does not return to the caller.
   void Bailout(const char* reason);
 
-  void TryIntrinsify();
+  // Returns 'true' if code generation for this function is complete, i.e.,
+  // no fall-through to regular code is needed and regular code contains no
+  // deopt ids.
+  bool TryIntrinsify();
 
   void GenerateRuntimeCall(intptr_t token_pos,
                            intptr_t deopt_id,