Update GH-9590 tests: fixing the fd_bigset limitation, not papering over it

These tests (arnaud-lb, GH-9602/80232de0e4b) verified that stream_select()
fails loudly and immediately once any watched descriptor exceeds
FD_SETSIZE, instead of silently dropping it from the fd_set and blocking
forever on a socket it can no longer see -- that was the real GH-9590
bug: a silently-dropped fd caused an indefinite, unexplained hang.

Our fd_bigset removes the cause of that bug on POSIX rather than just
detecting it: a descriptor past 1024 is no longer dropped, it's tracked
correctly. So the warning path these tests expected is now dead code
for this scenario, and running the tests unmodified exposed exactly
the failure mode they were designed to prevent: with nothing ever
written to the watched socket and no signal to stop it, `stream_select()`
now genuinely blocks on the (correctly-registered) high fd for the
full PHP_INT_MAX timeout instead of bailing out early, timing out CI
after 2 minutes per test on FreeBSD.

Updated both to assert the actual guarantee this PR provides: writing
to the paired socket and confirming stream_select() correctly reports
it as readable even past the old limit, with a finite timeout. Verified
manually against the patched build (posix_setrlimit's hard-limit-raise
via -1 fails as EPERM in this sandbox, so run-tests.php's own SKIPIF
skips them here, but the exact --FILE-- logic was run standalone with
an explicit hard limit and produces the new --EXPECT-- exactly).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: frodeborli

ext/standard/tests/streams/gh9590-001.phpt

@@ -1,5 +1,6 @@
 --TEST--
-Bug GH-9590 001 (stream_select does not abort upon exception or empty valid fd set)
+Bug GH-9590 001 (stream_select works correctly, without warning, past the traditional
+FD_SETSIZE descriptor limit on platforms where that limit has been lifted)
 --EXTENSIONS--
 posix
 --SKIPIF--
@@ -21,19 +22,17 @@ for ($i = 0; $i < 1023; $i++) {
 }
 
 list($a, $b) = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);
+fwrite($b, "x");
 
 $r = [$a];
 $w = $e = [];
-var_dump(stream_select($r, $w, $e, PHP_INT_MAX));
+var_dump(stream_select($r, $w, $e, 30));
+var_dump(fread($a, 1));
 
 ?>
---EXPECTF--
-Warning: stream_select(): You MUST recompile PHP with a larger value of FD_SETSIZE.
-It is set to 1024, but you have descriptors numbered at least as high as %d.
- --enable-fd-setsize=%d is recommended, but you may want to set it
-to equal the maximum number of open files supported by your system,
-in order to avoid seeing this error again at a later date. in %s on line %d
-bool(false)
+--EXPECT--
+int(1)
+string(1) "x"
 --CLEAN--
 <?php
 for ($i = 0; $i < 1023; $i++) {

ext/standard/tests/streams/gh9590-002.phpt

@@ -1,5 +1,7 @@
 --TEST--
-Bug GH-9590 002 (stream_select does not abort upon exception or empty valid fd set)
+Bug GH-9590 002 (a custom error handler that turns warnings into exceptions must not be
+spuriously triggered by stream_select() past the traditional FD_SETSIZE limit, on
+platforms where that limit has been lifted)
 --EXTENSIONS--
 posix
 --SKIPIF--
@@ -21,21 +23,19 @@ for ($i = 0; $i < 1023; $i++) {
 }
 
 list($a, $b) = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);
+fwrite($b, "x");
 
 set_error_handler(function($errno, $errstr) { throw new \Exception($errstr); });
 
 $r = [$a];
 $w = $e = [];
-var_dump(stream_select($r, $w, $e, PHP_INT_MAX));
+var_dump(stream_select($r, $w, $e, 30));
+var_dump(fread($a, 1));
 
 ?>
---EXPECTF--
-Fatal error: Uncaught Exception: stream_select(): You MUST recompile PHP with a larger value of FD_SETSIZE.
-It is set to 1024, but you have descriptors numbered at least as high as %d.
- --enable-fd-setsize=%d is recommended, but you may want to set it
-to equal the maximum number of open files supported by your system,
-in order to avoid seeing this error again at a later date. in %s:%d
-Stack trace:%a
+--EXPECT--
+int(1)
+string(1) "x"
 --CLEAN--
 <?php
 for ($i = 0; $i < 1023; $i++) {