Shrink libxml_doc_props struct (#11326)

These values are only ever bools, store them as bools.
Reduces the size from 40 bytes to 16 bytes on my system.

Author: nielsdos

ext/libxml/php_libxml.h

@@ -47,14 +47,14 @@ ZEND_BEGIN_MODULE_GLOBALS(libxml)
 ZEND_END_MODULE_GLOBALS(libxml)
 
 typedef struct _libxml_doc_props {
-	int formatoutput;
-	int validateonparse;
-	int resolveexternals;
-	int preservewhitespace;
-	int substituteentities;
-	int stricterror;
-	int recover;
 	HashTable *classmap;
+	bool formatoutput;
+	bool validateonparse;
+	bool resolveexternals;
+	bool preservewhitespace;
+	bool substituteentities;
+	bool stricterror;
+	bool recover;
 } libxml_doc_props;
 
 typedef struct _php_libxml_ref_obj {