clang/test/FixIt/fixit-unicode-with-utf8-output.c: Remove XFAIL.

It'd be another issue that the terminal and stdout(including redirects) with utf8. This test XPASSed on Win32, at least on Lit.

FYI, we don't use a triplet like "-win64" anywhere.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190559 91177308-0d34-0410-b5e6-96231b3b80d8