Test fix from https://github.com/php/php-src/pull/22717

To avoid eautoreconf in the meantime, we define the HAVE_PATHCONF and
HAVE_FPATHCONF via cppflags.

diff --git a/ext/posix/tests/posix_pathconf.phpt b/ext/posix/tests/posix_pathconf.phpt
index ba451c62df97..8df6e872119b 100644
--- a/ext/posix/tests/posix_pathconf.phpt
+++ b/ext/posix/tests/posix_pathconf.phpt
@@ -13,12 +13,15 @@ try {
 } catch (\ValueError $e) {
 	echo $e->getMessage(). "\n";
 }
-var_dump(posix_pathconf(str_repeat('non_existent', 4096), POSIX_PC_NAME_MAX));
-var_dump(posix_errno() != 0);
+
+/* POSIX specifically allows implementations to ignore the first
+ * argument if it will not affect the result. */
+$result = posix_pathconf(str_repeat('non_existent', 4096),
+                         POSIX_PC_NAME_MAX);
+var_dump( ($result == false && posix_errno() != 0) || is_int($result) );
 var_dump(posix_pathconf(sys_get_temp_dir(), POSIX_PC_PATH_MAX));
 ?>
 --EXPECTF--
 posix_pathconf(): Argument #1 ($path) must not be empty
-bool(false)
 bool(true)
 int(%d)