A number of performance tests are run with core lint enabled
In this MR !7188 (closed), I completely disabled core lint and it caused a number of compiler performance tests to significantly improve, which indicates they were previously been run with -dcore-lint enabled. As noted in #20825, this can skew measurements significantly.
https://gitlab.haskell.org/ghc/ghc/-/jobs/886317
-------------------------
Metric Decrease:
T10858
T11195
T11276
T11374
T11822
T14052
T14052Type
T17096
T17836
T18478
T18698a
T18698b
T1969
-------------------------
We should work out a robust way to stop these tests running with core-lint. Perhaps collect_compile_stats
should set -dno-core-lint
.