Upgrade to libxml 2.9.2 and libxslt 1.1.28

third_party/libxml/src/include/libxml/xmlversion.h.in

 /*
  * Summary: compile-time version informations
  * Description: compile-time version informations for the XML library
  *
  * Copy: See Copyright for the status of this software.
  *
  * Author: Daniel Veillard
  */
 
 #ifndef __XML_VERSION_H__
@@ skipping 80 matching lines @@
  * Whether the thread support is configured in
  */
 #if @WITH_THREADS@
 #if defined(_REENTRANT) || defined(__MT__) || \
     (defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE - 0 >= 199506L))
 #define LIBXML_THREAD_ENABLED
 #endif
 #endif
 
 /**
+ * LIBXML_THREAD_ALLOC_ENABLED:
+ *
+ * Whether the allocation hooks are per-thread
+ */
+#if @WITH_THREAD_ALLOC@
+#define LIBXML_THREAD_ALLOC_ENABLED
+#endif
+
+/**
  * LIBXML_TREE_ENABLED:
  *
  * Whether the DOM like tree manipulation API support is configured in
  */
 #if @WITH_TREE@
 #define LIBXML_TREE_ENABLED
 #endif
 
 /**
  * LIBXML_OUTPUT_ENABLED:
@@ skipping 273 matching lines @@
 
 /**
  * LIBXML_ZLIB_ENABLED:
  *
  * Whether the Zlib support is compiled in
  */
 #if @WITH_ZLIB@
 #define LIBXML_ZLIB_ENABLED
 #endif
 
+/**
+ * LIBXML_LZMA_ENABLED:
+ *
+ * Whether the Lzma support is compiled in
+ */
+#if @WITH_LZMA@
+#define LIBXML_LZMA_ENABLED
+#endif
+
 #ifdef __GNUC__
 #ifdef HAVE_ANSIDECL_H
 #include <ansidecl.h>
 #endif
 
 /**
  * ATTRIBUTE_UNUSED:
  *
  * Macro used to signal to GCC unused function parameters
  */
 
 #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
 
 /**
  * LIBXML_ATTR_ALLOC_SIZE:
  *
  * Macro used to indicate to GCC this is an allocator function
  */
 
 #ifndef LIBXML_ATTR_ALLOC_SIZE
-# if ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3)))
+# if (!defined(__clang__) && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3))))
 #  define LIBXML_ATTR_ALLOC_SIZE(x) __attribute__((alloc_size(x)))
 # else
 #  define LIBXML_ATTR_ALLOC_SIZE(x)
 # endif
 #else
 # define LIBXML_ATTR_ALLOC_SIZE(x)
 #endif
 
 /**
  * LIBXML_ATTR_FORMAT:
@@ skipping 31 matching lines @@
  */
 #define LIBXML_ATTR_FORMAT(fmt,args)
 #endif /* __GNUC__ */
 
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
 #endif