parser: Deprecate most public struct members

This will probably cause many warnings in downstream code abusing
libxml2 internals, but we can always undeprecate some members later.

python/generator.py

@@ -367,6 +367,11 @@ deprecated_funcs = {
     'xmlParseXMLDecl': True,
     'xmlParserHandlePEReference': True,
     'xmlParserHandleReference': True,
+    'xmlParserSetLineNumbers': True,
+    'xmlParserSetLoadSubset': True,
+    'xmlParserSetPedantic': True,
+    'xmlParserSetReplaceEntities': True,
+    'xmlParserSetValidate': True,
     'xmlPedanticParserDefault': True,
     'xmlRecoverDoc': True,
     'xmlRecoverFile': True,