This is new port containing FreeBSD specific Perl5 module Pthread::GetThreadId.

It provides Perl code with access to non-portable pthread_getthreadid_np(3)
function. It may be useful for Perl code running as hook/callback functions
in embedded threaded Perl environment when code has no direct control on thread creation.

For example, rlm_perl module of FreeRADIUS that may use multiple embedded Perl
instances, so that Perl native value of threads->tid is not unique.