Remove the test from r333801

In r333801 I added a test for a dump method that, for reasons I don't
understand, fails on an msvc bot:

http://lab.llvm.org:8011/builders/clang-x86-windows-msvc2015/builds/12306/

I'll remove the test for now to unblock the bot and try to look into why
there's a discrepancy on this platform later.

llvm-svn: 333807