/* This loop is actually executed only when end != REG_MISSING,
to rewrite <re>{0,n} as (<re>(<re>...<re>?)?)?... We have
already created the start+1-th copy. */
/* This loop is actually executed only when end != REG_MISSING,
to rewrite <re>{0,n} as (<re>(<re>...<re>?)?)?... We have
already created the start+1-th copy. */