devel/gpsim: Fix build with Clang 6
14bit-registers.cc:1778:23: error: invalid suffix on literal; C++11 requires a space between literal and identifier [-Wreserved-user-defined-literal]
Dprintf(("now=0x%"PRINTF_GINT64_MODIFIER"x\n",get_cycles().get()));
^... with a bazillion more like these in the code base
http://beefy11.nyi.freebsd.org/data/head-i386-default/p477696_s338122/logs/errors/gpsim-0.29.0_1.log