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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@244751 91177308-0d34-0410-b5e6-96231b3b80d8