Log Message:
lang/gcc5-aux: Upgrade version 20150422 => 20160603 (GCC 5.1 => 5.4)

The signal trampoline detection for NetBSD 7 and later is still broken.
Support for NetBSD 6.99 has been removed along with supporte for
32-bit DragonFly.  The modifications to the testsuite were misguided and
have also been removed.