Fix GH-21600: Remove xsltCleanupGlobals call in ext/xsl MSHUTDOWN.

The call to xsltCleanupGlobals() during module shutdown can cause
a segfault in xmlHashFree() when freeing libxslt internal hash
tables. This is the same class of shutdown cleanup issue that led
to xmlCleanupParser() being removed from ext/libxml. The process
is about to exit and the OS will reclaim all memory, making the
explicit cleanup both unnecessary and harmful.

close GH-21610

Author: devnexen

NEWS

@@ -31,6 +31,9 @@ PHP                                                                        NEWS
   . Fixed bug GH-21468 (Segfault in file_get_contents w/ a https URL
     and a proxy set). (ndossche)
 
+- XSL:
+  . Fixed bug GH-21600 (Segfault on module shutdown). (David Carlier)
+
 09 Apr 2026, PHP 8.4.20
 
 - Bz2:

ext/xsl/php_xsl.c

@@ -323,7 +323,6 @@ PHP_MSHUTDOWN_FUNCTION(xsl)
 	xsltUnregisterExtModuleFunction ((const xmlChar *) "function",
 				   (const xmlChar *) "http://php.net/xsl");
 	xsltSetGenericErrorFunc(NULL, NULL);
-	xsltCleanupGlobals();
 
 	return SUCCESS;
 }