Fix test suite under MSVC
Now that we can run the test suite with CMake, the following problems turned up with MSVC:
- Some encodings like Windows-1252 aren't supported because the MSVC build doesn't support iconv or ICU. This could be fixed by moving the offending tests to a separate directory and guard them with a libxml2 feature test.
-
runtest.exe
segfaults, apparently somewhere in the EXSLT dynamic tests. It's probably a stack overflow in the recursion test with the default limit of libxml2's XPath engine being too high.