Upgrade to libxml 2.9.2 and libxslt 1.1.28

third_party/libxml/linux/include/libxml/xmlversion.h

Index: third_party/libxml/linux/include/libxml/xmlversion.h
diff --git a/third_party/libxml/linux/include/libxml/xmlversion.h b/third_party/libxml/linux/include/libxml/xmlversion.h
index 9e849fa3796a51d56e8fd77200523fbc0184bc46..6fd386de05bb659f249e4dd329827a629d0e4a78 100644
--- a/third_party/libxml/linux/include/libxml/xmlversion.h
+++ b/third_party/libxml/linux/include/libxml/xmlversion.h
@@ -29,21 +29,21 @@ XMLPUBFUN void XMLCALL xmlCheckVersion(int version);
  *
  * the version string like "1.2.3"
  */
-#define LIBXML_DOTTED_VERSION "2.7.7"
+#define LIBXML_DOTTED_VERSION "2.9.2"
 
 /**
  * LIBXML_VERSION:
  *
  * the version number: 1.2.3 value is 10203
  */
-#define LIBXML_VERSION 20707
+#define LIBXML_VERSION 20902
 
 /**
  * LIBXML_VERSION_STRING:
  *
  * the version number string, 1.2.3 value is "10203"
  */
-#define LIBXML_VERSION_STRING "20707"
+#define LIBXML_VERSION_STRING "20902"
 
 /**
  * LIBXML_VERSION_EXTRA:
@@ -58,7 +58,7 @@ XMLPUBFUN void XMLCALL xmlCheckVersion(int version);
  * Macro to check that the libxml version in use is compatible with
  * the version the software has been compiled against
  */
-#define LIBXML_TEST_VERSION xmlCheckVersion(20707);
+#define LIBXML_TEST_VERSION xmlCheckVersion(20902);
 
 #ifndef VMS
 #if 0
@@ -98,6 +98,15 @@ XMLPUBFUN void XMLCALL xmlCheckVersion(int version);
 #endif
 
 /**
+ * LIBXML_THREAD_ALLOC_ENABLED:
+ *
+ * Whether the allocation hooks are per-thread
+ */
+#if 0
+#define LIBXML_THREAD_ALLOC_ENABLED
+#endif
+
+/**
  * LIBXML_TREE_ENABLED:
  *
  * Whether the DOM like tree manipulation API support is configured in
@@ -391,6 +400,15 @@ XMLPUBFUN void XMLCALL xmlCheckVersion(int version);
 #define LIBXML_ZLIB_ENABLED
 #endif
 
+/**
+ * LIBXML_LZMA_ENABLED:
+ *
+ * Whether the Lzma support is compiled in
+ */
+#if 0
+#define LIBXML_LZMA_ENABLED
+#endif
+
 #ifdef __GNUC__
 #ifdef HAVE_ANSIDECL_H
 #include <ansidecl.h>
@@ -403,7 +421,11 @@ XMLPUBFUN void XMLCALL xmlCheckVersion(int version);
  */
 
 #ifndef ATTRIBUTE_UNUSED
-#define ATTRIBUTE_UNUSED __attribute__((unused))
+# if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 7)))
+#  define ATTRIBUTE_UNUSED __attribute__((unused))
+# else
+#  define ATTRIBUTE_UNUSED
+# endif
 #endif
 
 /**