OS-4098 move open, close and fcntl into the kernel

@@ -72,16 +72,16 @@
         uint32_t auditing = AU_AUDITING();
         char startchar;
 
         if (filemode & (FSEARCH|FEXEC)) {
                 /*
-                 * Must be one or the other and neither FREAD nor FWRITE
+                 * Must be one or the other.
                  * Must not be any of FAPPEND FCREAT FTRUNC FXATTR FXATTRDIROPEN
-                 * XXX: Should these just be silently ignored?
+                 * XXX: Should these just be silently ignored like we
+                 * silently ignore FREAD|FWRITE?
                  */
-                if ((filemode & (FREAD|FWRITE)) ||
-                    (filemode & (FSEARCH|FEXEC)) == (FSEARCH|FEXEC) ||
+                if ((filemode & (FSEARCH|FEXEC)) == (FSEARCH|FEXEC) ||
                     (filemode & (FAPPEND|FCREAT|FTRUNC|FXATTR|FXATTRDIROPEN)))
                         return (set_errno(EINVAL));
         }
 
         if (startfd == AT_FDCWD) {