PPC: [es6] Re-implement rest parameters via desugaring.

Port 510baeac

Original commit message:
    Kills the kRestParameter bailout/disabled optimization, and fixes
    lazily parsed arrow functions with rest parameters.

    Supercedes https://crrev.com/1235153006/

R=caitpotter88@gmail.com, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, dstence@us.ibm.com
BUG=chromium:508074, v8:2160, v8:2700
LOG=N

Review URL: https://codereview.chromium.org/1318523006

Cr-Commit-Position: refs/heads/master@{#30574}

src/full-codegen/ppc/full-codegen-ppc.cc

@@ -290,28 +290,6 @@ void FullCodeGenerator::Generate() {
     SetVar(new_target_var, r3, r5, r6);
   }
 
-  // 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;
-
-    __ addi(r6, fp, Operand(StandardFrameConstants::kCallerSPOffset + offset));
-    __ LoadSmiLiteral(r5, Smi::FromInt(num_parameters));
-    __ LoadSmiLiteral(r4, Smi::FromInt(rest_index));
-    __ LoadSmiLiteral(r3, Smi::FromInt(language_mode()));
-    __ Push(r6, r5, r4, r3);
-    function_in_register_r4 = false;
-
-    RestParamAccessStub stub(isolate());
-    __ CallStub(&stub);
-
-    SetVar(rest_param, r3, r4, r5);
-  }
-
   Variable* arguments = scope()->arguments();
   if (arguments != NULL) {
     // Function uses arguments object.

src/ppc/code-stubs-ppc.cc

@@ -1985,32 +1985,6 @@ void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
 }
 
 
-void RestParamAccessStub::GenerateNew(MacroAssembler* masm) {
-  // Stack layout on entry.
-  //  sp[0] : language mode
-  //  sp[4] : index of rest parameter
-  //  sp[8] : number of parameters
-  //  sp[12] : receiver displacement
-
-  Label runtime;
-  __ LoadP(r5, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-  __ LoadP(r6, MemOperand(r5, StandardFrameConstants::kContextOffset));
-  __ CmpSmiLiteral(r6, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR), r0);
-  __ bne(&runtime);
-
-  // Patch the arguments.length and the parameters pointer.
-  __ LoadP(r4, MemOperand(r5, ArgumentsAdaptorFrameConstants::kLengthOffset));
-  __ StoreP(r4, MemOperand(sp, 2 * kPointerSize));
-  __ SmiToPtrArrayOffset(r6, r4);
-  __ add(r6, r5, r6);
-  __ addi(r6, r6, Operand(StandardFrameConstants::kCallerSPOffset));
-  __ StoreP(r6, MemOperand(sp, 3 * kPointerSize));
-
-  __ 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