The version of libxml2 required by c-index-test must be at least 2.5.3....

The version of libxml2 required by c-index-test must be at least 2.5.3. Considering that this version was released in 2003, you might think the check a bit ridiculous. Unfortunately, GnuWin32 ships with libxml2 2.4.12, which was released in 2001.

This allows us to have GnuWin32 on the PATH on Windows without causing compilation errors.

llvm-svn: 244751