Inline Array.shift() fast path instead of using a code stub.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 4386 matching lines @@
     bool is_js_array = from_map->instance_type() == JS_ARRAY_TYPE;
     TransitionElementsKindStub stub(isolate(), from_kind, to_kind, is_js_array);
     __ CallStub(&stub);
     RecordSafepointWithRegistersAndDoubles(
         instr->pointer_map(), 0, Safepoint::kLazyDeopt);
   }
   __ bind(&not_applicable);
 }
 
 
-void LCodeGen::DoArrayShift(LArrayShift* instr) {
-  ASSERT(ToRegister(instr->context()).is(cp));
-  ASSERT(ToRegister(instr->object()).is(a0));
-  ASSERT(ToRegister(instr->result()).is(v0));
-  ArrayShiftStub stub(isolate(), instr->hydrogen()->kind());
-  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
-}
-
-
 void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
   Register object = ToRegister(instr->object());
   Register temp = ToRegister(instr->temp());
   Label no_memento_found;
   __ TestJSArrayForAllocationMemento(object, temp, &no_memento_found,
                                      ne, &no_memento_found);
   DeoptimizeIf(al, instr->environment());
   __ bind(&no_memento_found);
 }
 
@@ skipping 1450 matching lines @@
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal