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

src/full-codegen/x87/full-codegen-x87.cc

Index: src/full-codegen/x87/full-codegen-x87.cc
diff --git a/src/full-codegen/x87/full-codegen-x87.cc b/src/full-codegen/x87/full-codegen-x87.cc
index 93ea2c0e2a28ef5b2d8e88a9142b4d98000eb200..c4d0a0615cc5c901fff102dc729bda1751e68554 100644
--- a/src/full-codegen/x87/full-codegen-x87.cc
+++ b/src/full-codegen/x87/full-codegen-x87.cc
@@ -2887,8 +2887,13 @@ 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());
+  __ mov(result_register(),
+         FieldOperand(result_register(), HeapObject::kMapOffset));
+  __ Push(FieldOperand(result_register(), Map::kPrototypeOffset));
 
   // Push the arguments ("left-to-right") on the stack.
   ZoneList<Expression*>* args = expr->arguments();