eventlog: Ensure that IPE output contains actual info table pointers
The refactoring in 866c736e introduced a rather subtle change in the semantics of the IPE eventlog output, changing the eventlog field from encoding info table pointers to "TNTC pointers" (which point to entry code when tables-next-to-code is enabled). Fix this.
Ultimately it is rather unsatisfactory how poorly the eventlog output
is tested. Perhaps we should consider adding ghc-events
as a dependency
in CI.
Fixes #22452 (closed).