apply _GL_ATTRIBUTE_PURE to some inline functions clang 3.4.2 flagged these inline functions as pure * lib/savewd.h (savewd_errno): Set _GL_ATTRIBUTE_PURE. * lib/sig-handler.h (get_handler): Likewise. * lib/stat-time.h (get_stat_{a,c,m,birth}time{,_ns}): Likewise. * lib/timespec.h (timespec_cmp, timespec_sign): Likewise.