Ticky profiling doesn't count stack allocations
In !1866 (comment 327969), I went through ticky profiles to ultimately find that they don't mention the hardest hitter. Since I was looking into the unregisterised backend, I thought that it might be related to stack allocation. I was baffled to find no mention of stack allocation in the ticky reports! So I asked aruond on IRC whether that's expected. @mpickering helpfully responded by grepping through GHC source, pointing me to https://gitlab.haskell.org/ghc/ghc/-/blob/c0709c1d1dcb60a238e9fc59ac33124e2a0c415d/includes/stg/Ticky.h#L210-219.
So it appears that we currently have no way of measuring stack allocation via ticky. Bummer!