Revert of PPC: [compiler] Drop the CompareNilIC.

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 a06afa44e37d7fc0c3243b15c30f27f52e4175ae..3db7bd5c17028c523f3b1083cef52390c2ea2f65 100644
--- a/src/ppc/interface-descriptors-ppc.cc
+++ b/src/ppc/interface-descriptors-ppc.cc
@@ -314,6 +314,13 @@
 }
 
 
+void CompareNilDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {r3};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
+
 void ToBooleanDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {r3};