PPC: Introduce a code stub version of Array.prototype.push

Port 1134688c

Original commit message:
    This roughly doubles performance for generic Array.prototype.push.

R=verwaest@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1823103002

Cr-Commit-Position: refs/heads/master@{#34999}

src/crankshaft/ppc/lithium-codegen-ppc.cc

@@ -3206,7 +3206,7 @@ void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
 
   if (instr->hydrogen()->from_inlined()) {
     __ subi(result, sp, Operand(2 * kPointerSize));
-  } else {
+  } else if (instr->hydrogen()->arguments_adaptor()) {
     // Check if the calling frame is an arguments adaptor frame.
     __ LoadP(scratch, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
     __ LoadP(
@@ -3228,6 +3228,8 @@ void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
       __ mr(result, scratch);
       __ bind(&done);
     }
+  } else {
+    __ mr(result, fp);
   }
 }
 

src/ppc/code-stubs-ppc.cc

@@ -77,6 +77,10 @@ void InternalArrayNoArgumentConstructorStub::InitializeDescriptor(
   InitializeInternalArrayConstructorDescriptor(isolate(), descriptor, 0);
 }
 
+void FastArrayPushStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
+  Address deopt_handler = Runtime::FunctionForId(Runtime::kArrayPush)->entry;
+  descriptor->Initialize(r3, deopt_handler, -1, JS_FUNCTION_STUB_MODE);
+}
 
 void InternalArraySingleArgumentConstructorStub::InitializeDescriptor(
     CodeStubDescriptor* descriptor) {

src/ppc/interface-descriptors-ppc.cc

@@ -287,6 +287,12 @@ void InternalArrayConstructorDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
+void FastArrayPushDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  // stack param count needs (arg count)
+  Register registers[] = {r3};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
 
 void CompareDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {