5218 posix definition of NULL
correct unistd.h and iso/stddef_iso.h
update gate source affected

@@ -96,11 +96,11 @@
 {
         uintptr_t                       cur_usb_dev;
         usba_device2devinfo_cbdata_t    *cb_data =
                             (usba_device2devinfo_cbdata_t *)cb_arg;
 
-        if ((cur_usb_dev = mdb_usba_get_usba_device(dip_addr)) == NULL) {
+        if ((cur_usb_dev = mdb_usba_get_usba_device(dip_addr)) == (uintptr_t)NULL) {
                 /*
                  * If there's no corresponding usba_device_t, this dip isn't
                  * a usb node.  Might be an sd node.  Ignore it.
                  */
 

@@ -180,11 +180,11 @@
  */
 int
 usba_list_walk_init(mdb_walk_state_t *wsp)
 {
         /* Must have a start addr.  */
-        if (wsp->walk_addr == NULL) {
+        if (wsp->walk_addr == (uintptr_t)NULL) {
                 mdb_warn("not a global walk.  Starting address required\n");
 
                 return (WALK_ERR);
         }
 

@@ -213,11 +213,11 @@
         status = wsp->walk_callback(wsp->walk_addr, &list_entry,
             wsp->walk_cbdata);
         wsp->walk_addr = (uintptr_t)list_entry.next;
 
         /* Check if we're at the last element */
-        if (wsp->walk_addr == NULL) {
+        if (wsp->walk_addr == (uintptr_t)NULL) {
 
                 return (WALK_DONE);
         }
 
         return (status);

@@ -235,11 +235,11 @@
  * (which address is not so easily obtainable).
  */
 int
 usb_pipe_handle_walk_init(mdb_walk_state_t *wsp)
 {
-        if (wsp->walk_addr == NULL) {
+        if (wsp->walk_addr == (uintptr_t)NULL) {
                 mdb_warn("not a global walk; usba_device_t required\n");
 
                 return (WALK_ERR);
         }
 

@@ -401,11 +401,11 @@
 int
 usba_device_walk_init(mdb_walk_state_t *wsp)
 {
         usba_list_entry_t       list_entry;
 
-        if (wsp->walk_addr != NULL) {
+        if (wsp->walk_addr != (uintptr_t)NULL) {
                 mdb_warn(
                     "global walk only.  Must be invoked without an address\n");
 
                 return (WALK_ERR);
         }

@@ -435,11 +435,11 @@
 {
         int             status;
         char            pathname[MAXNAMELEN];
         char            dname[MODMAXNAMELEN + 1] = "<unatt>"; /* Driver name */
         char            drv_statep[MODMAXNAMELEN+ 10];
-        uint_t          usb_flag  = NULL;
+        uint_t          usb_flag  = 0;
         boolean_t       no_driver_attached = FALSE;
         uintptr_t       dip_addr;
         struct dev_info devinfo;
 
         if (!(flags & DCMD_ADDRSPEC)) {

@@ -507,11 +507,11 @@
         mdb_printf("%-15s %2d   %-?p %s\n", dname, devinfo.devi_instance,
             dip_addr, pathname);
 
         if (usb_flag & USB_DUMP_VERBOSE) {
                 int             i;
-                uintptr_t       statep = NULL;
+                uintptr_t       statep = (uintptr_t)NULL;
                 char            *string_descr;
                 char            **config_cloud, **conf_str_descr;
                 usb_dev_descr_t usb_dev_descr;
                 usba_device_t   usba_device_struct;
 

@@ -715,11 +715,11 @@
 
                 return (DCMD_ERR);
         }
         local_debug_buf[debug_buf_size - 1] = '\0';
 
-        if (strlen(local_debug_buf) == NULL) {
+        if (strlen(local_debug_buf) == 0) {
 
                 return (DCMD_OK);
         }
 
         if ((term_p = strstr(local_debug_buf, ">>>>")) == NULL) {