Despite the compiler's claiming C99 compliance. What we probably
really need here is I_STDINT, or perhaps HAVE_INTMAX and
HAVE_UINTMAX, determined by Configure and friends. But in any case
07208e09d4435b4e72743076e0bc290ef4b34911 broke the build, so this
gets it going again for now.
#include "regcomp.h"
#ifndef HAS_C99
-# if __STDC_VERSION__ >= 199901L
+# if __STDC_VERSION__ >= 199901L && !defined(VMS)
# define HAS_C99 1
# endif
#endif