new classes: implement default constructors.

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 8fe07975c225d1cf34c47d629907afc3ccb49609..33521c6f17dcb320ef955b0d3a4bf1284a9f6938 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -2962,8 +2962,7 @@ void FullCodeGenerator::EmitResolvePossiblyDirectEval(int arg_count) {
 }
 
 
-void FullCodeGenerator::EmitLoadSuperConstructor(SuperReference* super_ref) {
-  DCHECK(super_ref != NULL);
+void FullCodeGenerator::EmitLoadSuperConstructor() {
   __ Push(Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   __ CallRuntime(Runtime::kGetPrototype, 1);
 }
@@ -3080,9 +3079,9 @@ void FullCodeGenerator::VisitCall(Call* expr) {
     if (FLAG_experimental_classes) {
       EmitSuperConstructorCall(expr);
     } else {
-      SuperReference* super_ref = callee->AsSuperReference();
-      EmitLoadSuperConstructor(super_ref);
+      EmitLoadSuperConstructor();
       __ Push(result_register());
+      SuperReference* super_ref = callee->AsSuperReference();
       VisitForStackValue(super_ref->this_var());
       EmitCall(expr, CallICState::METHOD);
     }
@@ -3153,10 +3152,10 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
   GetVar(result_register(), new_target_var);
   __ Push(result_register());
 
-  SuperReference* super_ref = expr->expression()->AsSuperReference();
-  EmitLoadSuperConstructor(super_ref);
+  EmitLoadSuperConstructor();
   __ Push(result_register());
 
+  SuperReference* super_ref = expr->expression()->AsSuperReference();
   Variable* this_var = super_ref->this_var()->var();
 
   GetVar(rax, this_var);
@@ -4071,6 +4070,55 @@ void FullCodeGenerator::EmitCallFunction(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitDefaultConstructorCallSuper(CallRuntime* expr) {
+  Variable* new_target_var = scope()->DeclarationScope()->new_target_var();
+  GetVar(result_register(), new_target_var);
+  __ Push(result_register());
+
+  EmitLoadSuperConstructor();
+  __ Push(result_register());
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label adaptor_frame, args_set_up, runtime;
+  __ movp(rdx, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
+  __ movp(rcx, Operand(rdx, StandardFrameConstants::kContextOffset));
+  __ Cmp(rcx, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
+  __ j(equal, &adaptor_frame);
+  // default constructor has no arguments, so no adaptor frame means no args.
+  __ movp(rax, Immediate(0));
+  __ jmp(&args_set_up);
+
+  // Copy arguments from adaptor frame.
+  {
+    __ bind(&adaptor_frame);
+    __ movp(rcx, Operand(rdx, ArgumentsAdaptorFrameConstants::kLengthOffset));
+    __ SmiToInteger64(rcx, rcx);
+
+    // Subtract 1 from arguments count, for new.target.
+    __ subp(rcx, Immediate(1));
+    __ movp(rax, rcx);
+    __ leap(rdx, Operand(rdx, rcx, times_pointer_size,
+                         StandardFrameConstants::kCallerSPOffset));
+    Label loop;
+    __ bind(&loop);
+    __ Push(Operand(rdx, -1 * kPointerSize));
+    __ subp(rdx, Immediate(kPointerSize));
+    __ decp(rcx);
+    __ j(not_zero, &loop);
+  }
+
+  __ bind(&args_set_up);
+  __ movp(rdi, Operand(rsp, rax, times_pointer_size, 0));
+
+  CallConstructStub stub(isolate(), SUPER_CONSTRUCTOR_CALL);
+  __ call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
+
+  __ Drop(1);
+
+  context()->Plug(result_register());
+}
+
+
 void FullCodeGenerator::EmitRegExpConstructResult(CallRuntime* expr) {
   RegExpConstructResultStub stub(isolate());
   ZoneList<Expression*>* args = expr->arguments();