[lldb][NFC] Force some logging on to TestCortexMExceptionUnwind.py
to possibly debug why this test fails on the
lldb-remote-linux-ubuntu CI bot. I'm sure the Target ArchSpec is
somehow ending up _not_ armv7m-apple-* like it should be, but I'd
like to gather a little more info before I just give up on running
this test on linux systems.