Do not call xmlCleanupParser from liblangtag

Despite its name, it is a cleanup function for libxml2 that must only be called
when the process as a whole no longer needs libxml2.  Calling it from a library
like liblangtag is not appropriate (just like liblangtag does not call
xmlInitParser, either).

In LibreOffice, this caused confusion about pthread keys for thread-local
storage (xmlCleanupParser calls pthread_key_delete, but apparently if libxml2 is
later used by unrelated code in LibreOffice again, it still uses the stale key,
and if that key is now reused via an unrelated pthread_key_create, arbitrary
crashes happen during thread termination in pthread's __nptl_deallocate_tsd).

Change-Id: I82cef8bc400d48f19eaa94f26d50d4b8589da106

liblangtag/liblangtag-0.2-xmlCleanupParser.patch

+--- misc/liblangtag-0.2/liblangtag/lt-xml.c
++++ misc/build/liblangtag-0.2/liblangtag/lt-xml.c
+@@ -101,8 +101,6 @@ lt_xml_read_subtag_registry(lt_xml_t  *x
+ 	if (xmlparser)
+ 		xmlFreeParserCtxt(xmlparser);
+ 
+-	xmlCleanupParser();
+-
+ 	if (err) {
+ 		if (error)
+ 			*error = g_error_copy(err);
+@@ -158,8 +156,6 @@ lt_xml_read_cldr_bcp47(lt_xml_t     *xml
+ 	if (xmlparser)
+ 		xmlFreeParserCtxt(xmlparser);
+ 
+-	xmlCleanupParser();
+-
+ 	if (err) {
+ 		if (error)
+ 			*error = g_error_copy(err);

liblangtag/makefile.mk

@@ -42,6 +42,7 @@ PATCH_FILES+=liblangtag-0.2-configure.patch
 PATCH_FILES+=liblangtag-0.2-datadir.patch
 PATCH_FILES+=liblangtag-0.2-msvc-warning.patch
 PATCH_FILES+=liblangtag-0.2-reg2xml-encoding-problem.patch
+PATCH_FILES+=liblangtag-0.2-xmlCleanupParser.patch
 
 CONFIGURE_DIR=.
 BUILD_DIR=$(CONFIGURE_DIR)