Sometimes avoid checking whether the receiver is an object in generated code.

src/full-codegen.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 377 matching lines @@
   // Record the OSR AST id corresponding to a stack check in the code.
   void RecordStackCheck(int osr_ast_id);
   // Emit a table of stack check ids and pcs into the code stream.  Return
   // the offset of the start of the table.
   unsigned EmitStackCheckTable();
 
   // Platform-specific return sequence
   void EmitReturnSequence();
 
   // Platform-specific code sequences for calls
-  void EmitCallWithStub(Call* expr);
+  void EmitCallWithStub(Call* expr, CallFunctionFlags flags);
   void EmitCallWithIC(Call* expr, Handle<Object> name, RelocInfo::Mode mode);
   void EmitKeyedCallWithIC(Call* expr, Expression* key, RelocInfo::Mode mode);
 
   // Platform-specific code for inline runtime calls.
   InlineFunctionGenerator FindInlineFunctionGenerator(Runtime::FunctionId id);
 
   void EmitInlineRuntimeCall(CallRuntime* expr);
 
 #define EMIT_INLINE_RUNTIME_CALL(name, x, y) \
   void Emit##name(ZoneList<Expression*>* arguments);
@@ skipping 340 matching lines @@
 
   friend class NestedStatement;
 
   DISALLOW_COPY_AND_ASSIGN(FullCodeGenerator);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FULL_CODEGEN_H_