arrange to create prototypes for generators

src/x64/code-stubs-x64.cc

 // Copyright 2012 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 140 matching lines @@
   Counters* counters = masm->isolate()->counters();
 
   Label gc;
   __ Allocate(JSFunction::kSize, rax, rbx, rcx, &gc, TAG_OBJECT);
 
   __ IncrementCounter(counters->fast_new_closure_total(), 1);
 
   // Get the function info from the stack.
   __ movq(rdx, Operand(rsp, 1 * kPointerSize));
 
-  int map_index = (language_mode_ == CLASSIC_MODE)
-      ? Context::FUNCTION_MAP_INDEX
-      : Context::STRICT_MODE_FUNCTION_MAP_INDEX;
+  int map_index = Context::FunctionMapIndex(language_mode_, is_generator_);
 
   // Compute the function map in the current native context and set that
   // as the map of the allocated object.
   __ movq(rcx, Operand(rsi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
   __ movq(rcx, FieldOperand(rcx, GlobalObject::kNativeContextOffset));
   __ movq(rbx, Operand(rcx, Context::SlotOffset(map_index)));
   __ movq(FieldOperand(rax, JSObject::kMapOffset), rbx);
 
   // Initialize the rest of the function. We don't have to update the
   // write barrier because the allocated object is in new space.
@@ skipping 6682 matching lines @@
 #endif
 
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64