PPC: Remove strong mode support from rest argument creation.

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 61e2b81c185d1b0ea3d4901ef5b6876f4b9f0f0e..b649f71ea35cc0c0921442c057d55eb21d773b13 100644
--- a/src/ppc/interface-descriptors-ppc.cc
+++ b/src/ppc/interface-descriptors-ppc.cc
@@ -66,7 +66,6 @@ const Register ArgumentsAccessNewDescriptor::parameter_pointer() { return r6; }
 const Register RestParamAccessDescriptor::parameter_count() { return r5; }
 const Register RestParamAccessDescriptor::parameter_pointer() { return r6; }
 const Register RestParamAccessDescriptor::rest_parameter_index() { return r7; }
-const Register RestParamAccessDescriptor::language_mode() { return r4; }
 
 
 const Register ApiGetterDescriptor::function_address() { return r5; }