Panic in GHC version 9.15.20260331: getStgArgFromTrivialArg
## Summary
I'm getting
```
<no location info>: error:
panic! (the 'impossible' happened)
GHC version 9.15.20260331:
getStgArgFromTrivialArg
scc<oneM1> eta_B0
Call stack:
CallStack (from HasCallStack):
pprPanic, called at compiler/GHC/CoreToStg.hs:626:13 in ghc-9.15-inplace:GHC.CoreToStg
Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug
```
## Steps to reproduce
```
cabal install --lib --allow-newer -w /home/mikolaj/r/ghc.T26831/ghc/_build/stage1/bin/ghc --constraint=hashable==1.5.0.0 --enable-profiling --profiling-detail=late optparse-applicative-0.19.0.0
```
It compiles fine with 9.12 and 9.14.
## Expected behavior
Compiles.
## Environment
* GHC version used: This is HEAD, but I don't remember right now if it also contains a MR near to being merged (and surely merged by this point, if so).
Optional:
* Operating System: Ubuntu
* System Architecture: amd64
issue