Auto merge of #99860 - oli-obk:revert_97346, r=pnkfelix

Revert "Rollup merge of #97346 - JohnTitor:remove-back-compat-hacks, …

…r=oli-obk"

This reverts commit c703d11, reversing
changes made to 64eb9ab.

it didn't apply cleanly, so now it works the same for RPIT and for TAIT instead of just working for RPIT, but we should keep those in sync anyway. It also exposed a TAIT bug (see the feature gated test that now ICEs).

r? `@pnkfelix`

fixes #99536

Author: bors