TestPerformance excluded from bild.py

Currently **bild.py** excludes tests in `TestPerformance`. However, this exclusion doesn't account for the difference between `TestPerformance` in the tool tests, and the new `TestPerformance` that's generated by the runtime test suite (#909). At least the latter should be run during the standard test cycle.

Start by reading bild.py's TestPerformance exclusion and compare it with the generated TestPerformance from the runtime test suite described in issue #909. Verify how the standard test cycle selects these tests, then ensure the runtime suite's TestPerformance is included without changing the intended tool-test behavior.

Written by the indexing model from the issue text.