forward-port feat/pgo fixes

Forward-port the genuinely-new fixes from feat/pgo (2026-06-09 .. 07-09)
into v3's reorganized layout:

- zig-cc.sh: prefix runtime-lib appends with `-x none` so the profile/crt/
  cpu_model archives don't poison the following files as `-x c` sources
- ZigToolchain: set ax_cv_have_func_attribute_ifunc=no under -flto
  (an ifunc in LTO bitcode crashes zig 0.16's lld during thin-link)
- php configure: add --with-sysconfdir option; strip build-time env vars
  from phpinfo's "Configure Command"
- ext-brotli / ext-zstd: switch to stable release/tag tarballs; brotli
  configures with --with-libbrotli
- ext-event: patch libevent http_connection.c to use a const peer address
  (both static and shared builds)
- ghrel downloader: prefer GitHub's /releases/latest (the semantically
  latest stable release) over publish-order iteration, so a newer-tagged
  prerelease (e.g. libevent 2.2.x-alpha) can't win over 2.1.x-stable

Commits already present in v3 were skipped: protobuf-latest + libaom
ENABLE_*=OFF (9398a667), the clang runtime -target flag (2adedc09), the
runtime-bits fail-hard half of 3823631a, and github prefer-stable's
prerelease skip (incl. the ghtar /releases/latest path, already in v3).

src/Package/Extension/event.php

@@ -35,12 +35,30 @@ class event extends PhpExtensionPackage
 
     #[BeforeStage('php', [php::class, 'makeForUnix'], 'ext-event')]
     #[PatchDescription('Prevent event extension compile error on macOS')]
+    #[PatchDescription('Patch libevent http_connection.c to use a const peer address')]
     public function patchBeforeMake(PackageInstaller $installer): void
     {
+        $php_src = $installer->getTargetPackage('php')->getSourceDir();
         // Prevent event extension compile error on macOS
         if (SystemTarget::getTargetOS() === 'Darwin') {
-            $php_src = $installer->getTargetPackage('php')->getSourceDir();
             FileSystem::replaceFileRegex("{$php_src}/main/php_config.h", '/^#define HAVE_OPENPTY 1$/m', '');
         }
+        $this->patchLibeventConstPeer("{$php_src}/ext/event");
+    }
+
+    #[BeforeStage('ext-event', [PhpExtensionPackage::class, 'makeForUnix'])]
+    #[PatchDescription('Patch libevent http_connection.c to use a const peer address')]
+    public function patchBeforeSharedMake(PhpExtensionPackage $pkg): void
+    {
+        $this->patchLibeventConstPeer($pkg->getSourceDir());
+    }
+
+    private function patchLibeventConstPeer(string $event_source_dir): bool
+    {
+        $file = "{$event_source_dir}/php8/classes/http_connection.c";
+        if (is_file($file) && FileSystem::replaceFileRegex($file, '/^\tchar \*address;$/m', "\tconst char *address;")) {
+            return true;
+        }
+        return false;
     }
 }

src/Package/Target/php.php

@@ -143,6 +143,7 @@ class php extends TargetPackage
         $package->addBuildOption('disable-opcache-jit', null, null, 'Disable opcache jit');
         $package->addBuildOption('with-config-file-path', null, InputOption::VALUE_REQUIRED, 'Set the path in which to look for php.ini', PHP_OS_FAMILY === 'Windows' ? null : '/usr/local/etc/php');
         $package->addBuildOption('with-config-file-scan-dir', null, InputOption::VALUE_REQUIRED, 'Set the directory to scan for .ini files after reading php.ini', PHP_OS_FAMILY === 'Windows' ? null : '/usr/local/etc/php/conf.d');
+        $package->addBuildOption('with-sysconfdir', null, InputOption::VALUE_REQUIRED, 'Set the sysconfdir (e.g. /etc/php-zts) used by configure (not available on Windows)');
         $package->addBuildOption('with-hardcoded-ini', 'I', InputOption::VALUE_IS_ARRAY | InputOption::VALUE_REQUIRED, 'Patch PHP source code, inject hardcoded INI');
         $package->addBuildOption('enable-zts', null, null, 'Enable thread safe support');
         $package->addBuildOption('no-smoke-test', null, InputOption::VALUE_OPTIONAL, 'Disable smoke test for specific SAPIs, or all if no value provided', false);

src/Package/Target/php/unix.php

@@ -75,6 +75,7 @@ trait unix
 
     #[BeforeStage('php', [self::class, 'configureForUnix'], 'php')]
     #[PatchDescription('Patch configure to use -std=gnu17 instead of -std=gnu23 for PHP <= 8.2')]
+    #[PatchDescription('Strip build-time env vars from phpinfo\'s "Configure Command"')]
     public function patchBeforeConfigure(TargetPackage $package): void
     {
         if (SystemTarget::isUnix() && self::getPHPVersionID() < 80300) {
@@ -84,6 +85,22 @@ trait unix
                 "for ac_arg in '' -std=gnu17",
             );
         }
+
+        // strip our build-time env vars from phpinfo's "Configure Command" ('|' delimiter: PHP_BUILD_PROVIDER may contain '#')
+        if (SystemTarget::isUnix()) {
+            FileSystem::replaceFileStr(
+                "{$package->getSourceDir()}/configure",
+                'for var in CFLAGS CXXFLAGS CPPFLAGS LDFLAGS EXTRA_LDFLAGS_PROGRAM LIBS CC CXX; do',
+                'for var in CFLAGS CXXFLAGS CPPFLAGS LDFLAGS EXTRA_LDFLAGS_PROGRAM LIBS CC CXX '
+                . 'PKG_CONFIG PKG_CONFIG_PATH EXTENSION_DIR OPENSSL_LIBS '
+                . 'PHP_BUILD_SYSTEM PHP_BUILD_PROVIDER PHP_BUILD_COMPILER PHP_BUILD_ARCH; do',
+            );
+            FileSystem::replaceFileStr(
+                "{$package->getSourceDir()}/configure",
+                'clean_configure_args=$(echo $clean_configure_args | $SED -e "s#\'$var=$val\'##")',
+                'clean_configure_args=$(echo $clean_configure_args | $SED -e "s|\'$var=$val\'||")',
+            );
+        }
     }
 
     #[Stage]
@@ -125,6 +142,9 @@ trait unix
         if ($option = $package->getBuildOption('with-config-file-scan-dir', false)) {
             $args[] = "--with-config-file-scan-dir={$option}";
         }
+        if ($option = $package->getBuildOption('with-sysconfdir', false)) {
+            $args[] = "--sysconfdir={$option}";
+        }
         // perform enable cli options
         $args[] = $installer->isPackageResolved('php-cli') ? '--enable-cli' : '--disable-cli';
         $args[] = $installer->isPackageResolved('php-fpm')