getopt-gnu: port back to Solaris 10 * gnulib-tool (func_emit_lib_Makefile_am) (func_emit_tests_Makefile_am): Don’t substitute things like $(GNULIB_${gl_include_guard_prefix}_UNISTD_H_GETOPT), as this mishandles unistd and getopt-gnu, which breaks ‘make check’ on Solaris 10 with getopt-gnu. * pygnulib/GLEmiter.py (lib_Makefile_am, tests_Makefile_am): Likewise, albeit hackier since I did not test this and so went with a trivial hack instead.