RunCompiler::new takes non-optional params, and optional
params can be set using set_*field_name* method.
finally `run` will forward all fields to `run_compiler`.
Allow tests to use
// ignore-remote
to ignore the test when using remote-test-{client,server}. In most
situations this would be covered by
// ignore-cross-compile
but I see no reason that a non-cross compiled remote test runner
shouldn't work.
