Add CMake detection for getopt.h and update json_parse.c to include it
only when HAVE_GETOPT_H is defined. Fixes AIX build failure.
# ---------------------------------
+# Check whether getopt.h exists
+check_include_file(getopt.h HAVE_GETOPT_H)
+
check_include_file(sys/resource.h HAVE_SYS_RESOURCE_H) # for getrusage
if (HAVE_SYS_RESOURCE_H)
check_symbol_exists(getrusage "sys/resource.h" HAVE_GETRUSAGE)
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
+#ifdef HAVE_GETOPT_H
#include <getopt.h>
+#endif
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>