new classes: implement new.target passing to superclass constructor.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index abb3d4a988e58c1cb7ab7e6b16deaaa4892b8007..e56fc4a5702f3662125b6b911d8bd61d88418c0c 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -539,6 +539,7 @@ void FunctionPrototypeStub::Generate(MacroAssembler* masm) {
 
 
 void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
+  CHECK(!has_new_target());
   // The key is in rdx and the parameter count is in rax.
   DCHECK(rdx.is(ArgumentsAccessReadDescriptor::index()));
   DCHECK(rax.is(ArgumentsAccessReadDescriptor::parameter_count()));
@@ -606,6 +607,8 @@ void ArgumentsAccessStub::GenerateNewSloppyFast(MacroAssembler* masm) {
   //  rbx: the mapped parameter count (untagged)
   //  rax: the allocated object (tagged).
 
+  CHECK(!has_new_target());
+
   Factory* factory = isolate()->factory();
 
   StackArgumentsAccessor args(rsp, 3, ARGUMENTS_DONT_CONTAIN_RECEIVER);
@@ -819,6 +822,7 @@ void ArgumentsAccessStub::GenerateNewSloppySlow(MacroAssembler* masm) {
   // rsp[8]  : number of parameters
   // rsp[16] : receiver displacement
   // rsp[24] : function
+  CHECK(!has_new_target());
 
   // Check if the calling frame is an arguments adaptor frame.
   Label runtime;
@@ -928,6 +932,13 @@ void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
   // Patch the arguments.length and the parameters pointer.
   __ bind(&adaptor_frame);
   __ movp(rcx, Operand(rdx, ArgumentsAdaptorFrameConstants::kLengthOffset));
+
+  if (has_new_target()) {
+    // Subtract 1 from smi-tagged arguments count.
+    __ SmiToInteger32(rcx, rcx);
+    __ decp(rcx);
+    __ Integer32ToSmi(rcx, rcx);
+  }
   __ movp(args.GetArgumentOperand(2), rcx);
   __ SmiToInteger64(rcx, rcx);
   __ leap(rdx, Operand(rdx, rcx, times_pointer_size,
@@ -2018,7 +2029,11 @@ void CallConstructStub::Generate(MacroAssembler* masm) {
   }
 
   // Pass original constructor to construct stub.
-  __ movp(rdx, rdi);
+  if (IsSuperConstructorCall()) {
+    __ movp(rdx, Operand(rsp, rax, times_pointer_size, 2 * kPointerSize));
+  } else {
+    __ movp(rdx, rdi);
+  }
 
   // Jump to the function-specific construct stub.
   Register jmp_reg = rcx;