[PATCH] D45715: [libcxx] [test] Remove nonportable that errc::is_a_directory produces "Is a directory" from ios_base::failure tests

[Marshall Clow via Phabricator via cfe-commits]

mclow.lists added a comment.

I'm fine with this change, but I'm wondering:

- if there are similar tests in the filesystem test suite, and you haven't tripped over them because you spelled your error message the same as we did.
- Should part of this test be moved into test/libcxx


https://reviews.llvm.org/D45715