Rollup merge of #142047 - cuviper:s390x-stack, r=oli-obk

Ensure stack in two places that affect s390x

In our Fedora s390x test results, we found two tests that started hitting stack
overflows in the 1.87.0 update. It seems to be related in some part to our use
of PGO as well, probably inlining more into stack frames that were already
recursive. The main points of recursion that I identified were:

- `ui/parser/survive-peano-lesson-queue.rs` in `ThirBuildCx::mirror_exprs`
- `ui/associated-consts/issue-93775.rs` in `Parser::parse_ty`

A couple new `ensure_sufficient_stack` calls will solve these tests.

Author: matthiaskrgr