slow validate failure: GivenCheckSwap in hpc way

Reproduce with

hadrian/build test --freeze1  --docs=none --flavour=slow-validate --test-speed=slow --only="GivenCheckSwap"

Looks like something needs to look through ticks.

-
-GivenCheckSwap.hs:11:9: warning: [-Woverlapping-patterns (in -Wdefault)]
-    Pattern match is redundant
-    In an equation for ‘g’: g y | False = ...
*** unexpected failure for GivenCheckSwap(hpc)