This removes the dependency LLDB API tests have on
lldb/third_party/Python/module/unittest2, and instead uses the standard
one provided by Python.
This does not actually remove the vendored dep yet, nor update the docs.
I'll do both those once this sticks.
Non-trivial changes to call out:
- expected failures (i.e. "bugnumber") don't have a reason anymore, so
those params were removed
- `assertItemsEqual` is now called `assertCountEqual`
- When a test is marked xfail, our copy of unittest2 considers failures
during teardown to be OK, but modern unittest does not. See
TestThreadLocal.py. (Very likely could be a real bug/leak).
- Our copy of unittest2 was patched to print all test results, even ones
that don't happen, e.g. `(5 passes, 0 failures, 1 errors, 0 skipped,
...)`, but standard unittest prints a terser message that omits test
result types that didn't happen, e.g. `OK (skipped=1)`. Our lit
integration parses this stderr and needs to be updated w/ that
expectation.
I tested this w/ `ninja check-lldb-api` on Linux. There's a good chance
non-Linux tests have similar quirks, but I'm not able to uncover those.
5b386158aa