PPC: [builtins] Sanitize the machinery around Construct calls.

src/ppc/interface-descriptors-ppc.cc

Index: src/ppc/interface-descriptors-ppc.cc
diff --git a/src/ppc/interface-descriptors-ppc.cc b/src/ppc/interface-descriptors-ppc.cc
index 58372e51ec83d5f34a78f1e4ec5ae9f39175a7ae..725d8f1986de49bf987fe6cde6d4ae0b323ceac4 100644
--- a/src/ppc/interface-descriptors-ppc.cc
+++ b/src/ppc/interface-descriptors-ppc.cc
@@ -204,6 +204,16 @@ void CallTrampolineDescriptor::InitializePlatformSpecific(
 }
 
 
+void ConstructTrampolineDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  // r3 : number of arguments
+  // r4 : the target to call
+  // r6 : the new target
+  Register registers[] = {r4, r6, r3};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
+
 void RegExpConstructResultDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {r5, r4, r3};