Use consistent style to check DEBUG macro in regex_internal.c The DEBUG macro is checked using both #if and #ifdef in regex_internal.c. Make this consistent with mktime, where we use "#if defined DEBUG && DEBUG", to be compatible with gnulib as well as glibc style. regex: Make #if/#ifdef usage consistent for DEBUG * lib/regex_internal.c: Use "#if defined DEBUG && DEBUG" instead of the inconsistent usage of #if and #ifdef as that works with both Glibc and Gnulib's style.