in the re extension, their symbols have to be exported.
p4raw-id: //depot/perl@12633
Ap |MGVTBL*|get_vtbl |int vtbl_id
p |char* |pv_display |SV *dsv|char *pv|STRLEN cur|STRLEN len \
|STRLEN pvlim
-p |char* |pv_uni_display |SV *dsv|U8 *spv|STRLEN len \
+Ap |char* |pv_uni_display |SV *dsv|U8 *spv|STRLEN len \
|STRLEN pvlim|UV flags
-p |char* |sv_uni_display |SV *dsv|SV *ssv|STRLEN pvlim|UV flags
+Ap |char* |sv_uni_display |SV *dsv|SV *ssv|STRLEN pvlim|UV flags
Afp |void |dump_indent |I32 level|PerlIO *file|const char* pat|...
Ap |void |dump_vindent |I32 level|PerlIO *file|const char* pat \
|va_list *args
Perl_sv_setsv_mg
Perl_sv_usepvn_mg
Perl_get_vtbl
+Perl_pv_uni_display
+Perl_sv_uni_display
Perl_dump_indent
Perl_dump_vindent
Perl_do_gv_dump