Roll libxml to 2.9.3

third_party/libxml/src/m4/ltversion.m4

Index: third_party/libxml/src/m4/ltversion.m4
diff --git a/third_party/tcmalloc/vendor/m4/ltversion.m4 b/third_party/libxml/src/m4/ltversion.m4
similarity index 65%
copy from third_party/tcmalloc/vendor/m4/ltversion.m4
copy to third_party/libxml/src/m4/ltversion.m4
index f3c5309802447a3b341b1a2c5e4d74ec138b311a..fa04b52a3bf868bd57e7ba796d64385a51e7ec5a 100644
--- a/third_party/tcmalloc/vendor/m4/ltversion.m4
+++ b/third_party/libxml/src/m4/ltversion.m4
@@ -1,23 +1,23 @@
 # ltversion.m4 -- version numbers			-*- Autoconf -*-
 #
-#   Copyright (C) 2004 Free Software Foundation, Inc.
+#   Copyright (C) 2004, 2011-2015 Free Software Foundation, Inc.
 #   Written by Scott James Remnant, 2004
 #
 # This file is free software; the Free Software Foundation gives
 # unlimited permission to copy and/or distribute it, with or without
 # modifications, as long as this notice is preserved.
 
-# Generated from ltversion.in.
+# @configure_input@
 
-# serial 3017 ltversion.m4
+# serial 4179 ltversion.m4
 # This file is part of GNU Libtool
 
-m4_define([LT_PACKAGE_VERSION], [2.2.6b])
-m4_define([LT_PACKAGE_REVISION], [1.3017])
+m4_define([LT_PACKAGE_VERSION], [2.4.6])
+m4_define([LT_PACKAGE_REVISION], [2.4.6])
 
 AC_DEFUN([LTVERSION_VERSION],
-[macro_version='2.2.6b'
-macro_revision='1.3017'
+[macro_version='2.4.6'
+macro_revision='2.4.6'
 _LT_DECL(, macro_version, 0, [Which release of libtool.m4 was used?])
 _LT_DECL(, macro_revision, 0)
 ])