X87: Switch CallConstructStub to take new.target in register.

src/x87/interface-descriptors-x87.cc

Index: src/x87/interface-descriptors-x87.cc
diff --git a/src/x87/interface-descriptors-x87.cc b/src/x87/interface-descriptors-x87.cc
index 09ea37c67e84178ab2a582a7e9d8b5810981e736..279b42677c1e84cf0b09561935a05ff3508313cd 100644
--- a/src/x87/interface-descriptors-x87.cc
+++ b/src/x87/interface-descriptors-x87.cc
@@ -170,12 +170,12 @@ void CallConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // eax : number of arguments
   // ebx : feedback vector
-  // edx : (only if ebx is not the megamorphic symbol) slot in feedback
-  //       vector (Smi)
+  // ecx : original constructor (for IsSuperConstructorCall)
+  // edx : slot in feedback vector (Smi, for RecordCallTarget)
   // edi : constructor function
   // TODO(turbofan): So far we don't gather type feedback and hence skip the
   // slot parameter, but ArrayConstructStub needs the vector to be undefined.
-  Register registers[] = {eax, edi, ebx};
+  Register registers[] = {eax, edi, ecx, ebx};
   data->InitializePlatformSpecific(arraysize(registers), registers, NULL);
 }