Partial revert of rest parameter desugaring.

src/full-codegen/mips/full-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_MIPS
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 251 matching lines @@
     SetVar(this_function_var, a1, a0, a2);
   }
 
   // Possibly set up a local binding to the new target value.
   Variable* new_target_var = scope()->new_target_var();
   if (new_target_var != nullptr) {
     Comment cmnt(masm_, "[ new.target");
     SetVar(new_target_var, a3, a0, a2);
   }
 
+  // Possibly allocate RestParameters
+  int rest_index;
+  Variable* rest_param = scope()->rest_parameter(&rest_index);
+  if (rest_param) {
+    Comment cmnt(masm_, "[ Allocate rest parameter array");
+
+    int num_parameters = info->scope()->num_parameters();
+    int offset = num_parameters * kPointerSize;
+
+    __ Addu(a3, fp, Operand(StandardFrameConstants::kCallerSPOffset + offset));
+    __ li(a2, Operand(Smi::FromInt(num_parameters)));
+    __ li(a1, Operand(Smi::FromInt(rest_index)));
+    __ li(a0, Operand(Smi::FromInt(language_mode())));
+    __ Push(a3, a2, a1, a0);
+    function_in_register_a1 = false;
+
+    RestParamAccessStub stub(isolate());
+    __ CallStub(&stub);
+
+    SetVar(rest_param, v0, a1, a2);
+  }
+
   Variable* arguments = scope()->arguments();
   if (arguments != NULL) {
     // Function uses arguments object.
     Comment cmnt(masm_, "[ Allocate arguments object");
     DCHECK(a1.is(ArgumentsAccessNewDescriptor::function()));
     if (!function_in_register_a1) {
       // Load this again, if it's used by the local context below.
       __ lw(a1, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
     }
     // Receiver is just before the parameters on the caller's stack.
@@ skipping 4564 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS