CV* (*Perl_newXS)(pTHX_ const char *name, XSUBADDR_t subaddr, const char *filename);

....
Perl_newXS = (CV* (*)(pTHX_ const char *name, XSUBADDR_t subaddr, const char *filename) )dlsym(handle, "Perl_newXS");

##</code><code>##

 error: ‘Perl_newXS’ redeclared as different kind of symbol
/usr/lib64/perl5/CORE/proto.h:2517:19: note: previous declaration of ‘Perl_newXS’ was here
 2517 | PERL_CALLCONV CV* Perl_newXS(pTHX_ const char *name, XSUBADDR_t subaddr, const char *filename);