gettimeofday: Remove workaround for Mac OS X 10.0. * m4/gettimeofday.m4 (gl_FUNC_GETTIMEOFDAY_CLOBBER): Remove macro. (gl_FUNC_GETTIMEOFDAY): Don't invoke it. * lib/gettimeofday.c: Don't include localtime-buffer.h. (gettimeofday): Don't test GETTIMEOFDAY_CLOBBERS_LOCALTIME. * lib/localtime.c: Don't test GETTIMEOFDAY_CLOBBERS_LOCALTIME. * modules/gettimeofday (Depends-on): Remove localtime-buffer. * modules/localtime-buffer: Remove file. * lib/localtime-buffer.h: Remove file. * lib/localtime-buffer.c: Remove file. * m4/localtime-buffer.m4: Remove file. * MODULES.html.sh (Date and time <time.h>): Remove localtime-buffer.