jscott/which: A small implementation of 'which', a utility showing where programs can be found

A small implementation of 'which', a utility showing where programs can be found

John Scott 61fc96e376 Define _XOPEN_SOURCE to 700.		%!s(int64=3) %!d(string=hai) anos
meson.build	d00a50c71b Stop assuming strerror() is thread-safe.	%!s(int64=3) %!d(string=hai) anos
which.c	61fc96e376 Define _XOPEN_SOURCE to 700.	%!s(int64=3) %!d(string=hai) anos