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

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 962c2f030e24eafc7bf538a735d3e91b67277dac..ae23a6e09f00132bcafbbbbfb1117deef342d2c8 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -320,16 +320,6 @@ void ElementsTransitionAndStoreStub::InitializeInterfaceDescriptor(
 }
 
 
-void ArrayShiftStub::InitializeInterfaceDescriptor(
-    CodeStubInterfaceDescriptor* descriptor) {
-  static Register registers[] = { a0 };
-  descriptor->register_param_count_ = 1;
-  descriptor->register_params_ = registers;
-  descriptor->deoptimization_handler_ =
-      Builtins::c_function_address(Builtins::c_ArrayShift);
-}
-
-
 void BinaryOpICStub::InitializeInterfaceDescriptor(
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { a1, a0 };