[es6] Consistently use %_GetSuperConstructor to implement super calls.

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

Index: src/full-codegen/ppc/full-codegen-ppc.cc
diff --git a/src/full-codegen/ppc/full-codegen-ppc.cc b/src/full-codegen/ppc/full-codegen-ppc.cc
index 3268820edf9594352cd4cec5922b204e8e332221..212e90d115ff9c5687d3db3b3eb5ee725f8d26cb 100644
--- a/src/full-codegen/ppc/full-codegen-ppc.cc
+++ b/src/full-codegen/ppc/full-codegen-ppc.cc
@@ -3003,8 +3003,15 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
       expr->expression()->AsSuperCallReference();
   DCHECK_NOT_NULL(super_call_ref);
 
-  EmitLoadSuperConstructor(super_call_ref);
-  __ push(result_register());
+  // Push the super constructor target on the stack (may be null,
+  // but the Construct builtin can deal with that properly).
+  VisitForAccumulatorValue(super_call_ref->this_function_var());
+  __ AssertFunction(result_register());
+  __ LoadP(result_register(),
+           FieldMemOperand(result_register(), HeapObject::kMapOffset));
+  __ LoadP(result_register(),
+           FieldMemOperand(result_register(), Map::kPrototypeOffset));
+  __ Push(result_register());
 
   // Push the arguments ("left-to-right") on the stack.
   ZoneList<Expression*>* args = expr->arguments();