Update freetype sources (2.6.2) in third party.

third_party/freetype2/src/builds/unix/ft-munmap.m4

Index: third_party/freetype2/src/builds/unix/ft-munmap.m4
diff --git a/third_party/freetype2/src/builds/unix/ft-munmap.m4 b/third_party/freetype2/src/builds/unix/ft-munmap.m4
new file mode 100644
index 0000000000000000000000000000000000000000..72b08645dd6ce431c5d3350bb5c9d2c71fcc0109
--- /dev/null
+++ b/third_party/freetype2/src/builds/unix/ft-munmap.m4
@@ -0,0 +1,32 @@
+## FreeType specific autoconf tests
+#
+# Copyright 2002-2015 by
+# David Turner, Robert Wilhelm, and Werner Lemberg.
+#
+# This file is part of the FreeType project, and may only be used, modified,
+# and distributed under the terms of the FreeType project license,
+# LICENSE.TXT.  By continuing to use, modify, or distribute this file you
+# indicate that you have read the license and understand and accept it
+# fully.
+
+# serial 2
+
+AC_DEFUN([FT_MUNMAP_PARAM],
+  [AC_MSG_CHECKING([for munmap's first parameter type])
+   AC_COMPILE_IFELSE([
+       AC_LANG_SOURCE([[
+
+#include <unistd.h>
+#include <sys/mman.h>
+int munmap(void *, size_t);
+
+       ]])
+     ],
+     [AC_MSG_RESULT([void *])
+      AC_DEFINE([MUNMAP_USES_VOIDP],
+        [],
+        [Define to 1 if the first argument of munmap is of type void *])],
+     [AC_MSG_RESULT([char *])])
+  ])
+
+# end of ft-munmap.m4