renameat, renameatu: Fix warning on Android

[Bruno Haible]

Building a testdir on Android, I see this warning:

../../gllib/renameatu.c:106:13: warning: call to undeclared function 
'renameat2'; ISO C99 and later do not support implicit function declarations 
[-Wimplicit-function-declaration]

The cause is this API-level conditional declaration:

/usr/include/stdio.h:int renameat2(int __old_dir_fd, const char* __old_path, 
int __new_dir_fd, const char* __new_path, unsigned __flags) __INTRODUCED_IN(30);

This patch fixes the warning.


2023-01-10  Bruno Haible  <bruno@clisp.org>

        renameat, renameatu: Fix warning on Android.
        * m4/renameat.m4 (gl_FUNC_RENAMEAT): Test for renameat2 using
        gl_CHECK_FUNCS_ANDROID instead of AC_CHECK_FUNCS_ONCE.

diff --git a/m4/renameat.m4 b/m4/renameat.m4
index 7e38e436a3..3780578663 100644
--- a/m4/renameat.m4
+++ b/m4/renameat.m4
@@ -1,4 +1,4 @@
-# serial 3
+# serial 4
 # See if we need to provide renameat replacement.
 
 dnl Copyright (C) 2009-2023 Free Software Foundation, Inc.
@@ -15,11 +15,12 @@ AC_DEFUN([gl_FUNC_RENAMEAT],
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_CHECK_HEADERS([linux/fs.h])
-  AC_CHECK_FUNCS_ONCE([renameat renameat2])
+  AC_CHECK_FUNCS_ONCE([renameat])
   if test $ac_cv_func_renameat = no; then
     HAVE_RENAMEAT=0
   elif test $REPLACE_RENAME = 1; then
     dnl Solaris 9 and 10 have the same bugs in renameat as in rename.
     REPLACE_RENAMEAT=1
   fi
+  gl_CHECK_FUNCS_ANDROID([renameat2], [[#include <stdio.h>]])
 ])