Log Message:
Update to 1.9754

Upstream changes:
1.9754 [2018-02-16]
 - unify the gettimeofday() and time() forked code
   that had near identical code paths for MacOS Classic
   (which has two unusual features: unsigned time_t,
   and a special tz struct member), and for non-MacOS Classic
 - tv_interval should be implemented in XS
   [rt.cpan.org #106456]
   thanks to Sergey Aleynikov (suggested implementation simplified
   by the above-mentioned MacOS Classic simplification)