Fixup for cbe42a9d5f. Increase values for testing the overall lit
timeout (--max-time) which wasn't enough for the test to complete on
very slow build bots.
Track and print the number of skipped tests. Skipped tests are tests
that should have been executed but weren't due to:
* user interrupt [Ctrl+C]
* --max-time (overall lit timeout)
* --max-failures
This is part of a larger effort to ensure that all discovered tests are
properly accounted for.
Add test for overall lit timeout feature (`--max-time` option) to
observe skipped tests. Extend test for `--max-failures` option.
Reviewed By: jdenny
Differential Revision: https://reviews.llvm.org/D77819