* A bunch of them require objc_interop because they import code containing
Objective-C.
* Many others fail on Ubuntu 14.04 because the C++ there doesn't have a
functional std::regex implementation which is required by the
`complete-test` tool.
It may be possible to adjust some of these tests in the future to not
need these extra requirements, but this is a straightforward way to
clean up Linux test results for now.
