Fix "PPC: Use register arguments for RestParamAccessStub".

Fix build break.

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

Review URL: https://codereview.chromium.org/1556063004

Cr-Commit-Position: refs/heads/master@{#33099}

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

@@ -274,13 +274,13 @@ void FullCodeGenerator::Generate() {
     int offset = num_parameters * kPointerSize;
 
     __ LoadSmiLiteral(RestParamAccessDescriptor::parameter_count(),
-                      Operand(Smi::FromInt(num_parameters)));
+                      Smi::FromInt(num_parameters));
     __ addi(RestParamAccessDescriptor::parameter_pointer(), fp,
             Operand(StandardFrameConstants::kCallerSPOffset + offset));
     __ LoadSmiLiteral(RestParamAccessDescriptor::rest_parameter_index(),
-                      Operand(Smi::FromInt(rest_index)));
+                      Smi::FromInt(rest_index));
     __ LoadSmiLiteral(RestParamAccessDescriptor::language_mode(),
-                      Operand(Smi::FromInt(language_mode())));
+                      Smi::FromInt(language_mode()));
     DCHECK(r4.is(RestParamAccessDescriptor::language_mode()));
     function_in_register_r4 = false;