Switch CallConstructStub to take new.target in register.

src/arm64/full-codegen-arm64.cc

Index: src/arm64/full-codegen-arm64.cc
diff --git a/src/arm64/full-codegen-arm64.cc b/src/arm64/full-codegen-arm64.cc
index ad8bb90947a77802b7c952fe0ddbcd6e32264cfb..d023a609a49f0930c11971ee6e18fb113f3094e2 100644
--- a/src/arm64/full-codegen-arm64.cc
+++ b/src/arm64/full-codegen-arm64.cc
@@ -3074,9 +3074,6 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
       expr->expression()->AsSuperCallReference();
   DCHECK_NOT_NULL(super_call_ref);
 
-  VariableProxy* new_target_proxy = super_call_ref->new_target_var();
-  VisitForStackValue(new_target_proxy);
-
   EmitLoadSuperConstructor(super_call_ref);
   __ push(result_register());
 
@@ -3091,6 +3088,10 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
   // constructor invocation.
   SetConstructCallPosition(expr);
 
+  // Load original constructor into x4.
+  VisitForAccumulatorValue(super_call_ref->new_target_var());
+  __ mov(x4, result_register());

[jbramley, 2015/07/14 16:57:35]

We prefer the MacroAssembler's "__ Mov(...)" in ARM64, for consistency, even
though it doesn't make any difference in this particular case. (The lower-case
Assembler versions are usually reserved for critical sections in
InstructionAccurateScopes.)

[Michael Starzinger, 2015/07/15 07:36:36]

Done. One of these days I am gonna remember that, I promise. :)

+
   // Load function and argument count into x1 and x0.
   __ Mov(x0, arg_count);
   __ Peek(x1, arg_count * kXRegSize);
@@ -3111,8 +3112,6 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
   CallConstructStub stub(isolate(), SUPER_CALL_RECORD_TARGET);
   __ Call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
 
-  __ Drop(1);
-
   RecordJSReturnSite(expr);
 
   EmitInitializeThisAfterSuper(super_call_ref, expr->CallFeedbackICSlot());
@@ -4043,6 +4042,9 @@ void FullCodeGenerator::EmitDefaultConstructorCallSuper(CallRuntime* expr) {
   __ CallRuntime(Runtime::kGetPrototype, 1);
   __ Push(result_register());
 
+  // Load original constructor into x4.
+  __ Peek(x4, 1 * kPointerSize);
+
   // Check if the calling frame is an arguments adaptor frame.
   Label adaptor_frame, args_set_up, runtime;
   __ Ldr(x11, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));