gnulib-tool: fix tests of 'extensions' module This complements f8fe25fab60e3c687a124 commit. * gnulib-tool (func_emit_pre_early_macros): New function, it wraps emitting of initial gl_EARLY macros. (func_import, func_create_testdir): All dumps of gl_PROG_AR_RANLIB replaced with func_emit_pre_early_macros call.