Rollup merge of #152417 - Zalathar:arena-alloc, r=nnethercote

Move the needs-drop check for `arena_cache` queries out of macro code

This is slightly simpler than before, because now the macro only needs to call a single function, and can just unconditionally supply `tcx` and a typed arena.

There should be no actual change to compiler behaviour.

Author: JonathanBrouwer