#define PL_sv_no (*Perl_Isv_no_ptr(aTHX))
#undef PL_sv_objcount
#define PL_sv_objcount (*Perl_Isv_objcount_ptr(aTHX))
+#undef PL_sv_placeholder
+#define PL_sv_placeholder (*Perl_Isv_placeholder_ptr(aTHX))
#undef PL_sv_root
#define PL_sv_root (*Perl_Isv_root_ptr(aTHX))
#undef PL_sv_undef