doc: test: clarify that -rwx don't just check perm bits

* src/test.c (usage): State that -rwx is determined by
user access, rather than permission bits.
* doc/coreutils.texi (Access permission tests): Likewise.
* man/test.x [SEE ALSO]: access(2).
Fixes https://bugs.gnu.org/54338

doc/coreutils.texi

@@ -13451,7 +13451,7 @@ True if @var{file} exists and has its @dfn{sticky} bit set.
 @item -r @var{file}
 @opindex -r
 @cindex readable file check
-True if @var{file} exists and read permission is granted.
+True if @var{file} exists and the user has read access.
 
 @item -u @var{file}
 @opindex -u
@@ -13461,12 +13461,12 @@ True if @var{file} exists and has its set-user-ID bit set.
 @item -w @var{file}
 @opindex -w
 @cindex writable file check
-True if @var{file} exists and write permission is granted.
+True if @var{file} exists and the user has write access.
 
 @item -x @var{file}
 @opindex -x
 @cindex executable file check
-True if @var{file} exists and execute permission is granted
+True if @var{file} exists and the user has execute access
 (or search permission, if it is a directory).
 
 @item -O @var{file}

man/test.x

@@ -1,3 +1,8 @@
+'\" Copyright (C) 1998-2022 Free Software Foundation, Inc.
+'\"
+'\" This is free software.  You may redistribute copies of it under the terms
+'\" of the GNU General Public License <https://www.gnu.org/licenses/gpl.html>.
+'\" There is NO WARRANTY, to the extent permitted by law.
 [NAME]
 test \- check file types and compare values
 [SYNOPSIS]
@@ -17,3 +22,5 @@ test \- check file types and compare values
 .I OPTION
 [DESCRIPTION]
 .\" Add any additional description here
+[SEE ALSO]
+access(2)

src/test.c

@@ -750,15 +750,15 @@ EXPRESSION is true or false and sets exit status.  It is one of:\n\
   -N FILE     FILE exists and has been modified since it was last read\n\
   -O FILE     FILE exists and is owned by the effective user ID\n\
   -p FILE     FILE exists and is a named pipe\n\
-  -r FILE     FILE exists and read permission is granted\n\
+  -r FILE     FILE exists and the user has read access\n\
   -s FILE     FILE exists and has a size greater than zero\n\
 "), stdout);
       fputs (_("\
   -S FILE     FILE exists and is a socket\n\
   -t FD       file descriptor FD is opened on a terminal\n\
   -u FILE     FILE exists and its set-user-ID bit is set\n\
-  -w FILE     FILE exists and write permission is granted\n\
-  -x FILE     FILE exists and execute (or search) permission is granted\n\
+  -w FILE     FILE exists and the user has write access\n\
+  -x FILE     FILE exists and the user has execute (or search) access\n\
 "), stdout);
       fputs (_("\
 \n\