Partial revert of rest parameter desugaring.

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 6f48d4dd6bfda9854f17ca919659e85858ace9a3..4df39f6195090d69b9b7c7300ee0c3e1c4af663d 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -1977,6 +1977,34 @@ void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
 }
 
 
+void RestParamAccessStub::GenerateNew(MacroAssembler* masm) {
+  // sp[0] : language mode
+  // sp[4] : index of rest parameter
+  // sp[8] : number of parameters
+  // sp[12] : receiver displacement
+  // Check if the calling frame is an arguments adaptor frame.
+
+  Label runtime;
+  __ lw(a2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a3, MemOperand(a2, StandardFrameConstants::kContextOffset));
+  __ Branch(&runtime, ne, a3,
+            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+
+  // Patch the arguments.length and the parameters pointer.
+  __ lw(a1, MemOperand(a2, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ sw(a1, MemOperand(sp, 2 * kPointerSize));
+  __ sll(at, a1, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(a3, a2, Operand(at));
+
+  __ Addu(a3, a3, Operand(StandardFrameConstants::kCallerSPOffset));
+  __ sw(a3, MemOperand(sp, 3 * kPointerSize));
+
+  // Do the runtime call to allocate the arguments object.
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewRestParam, 4, 1);
+}
+
+
 void RegExpExecStub::Generate(MacroAssembler* masm) {
   // Just jump directly to runtime if native RegExp is not selected at compile
   // time or if regexp entry in generated code is turned off runtime switch or