Auto merge of #139327 - cjgillot:gvn-place, r=oli-obk

Allow GVN to produce places and not just locals.

That may be too big of a hammer, as we may introduce new deref projections (possible UB footgun + probably not good for perf).

The second commit opts out of introducing projections that don't have a stable offset, which is probably what we want. Hence no new Deref and no new Index projections.

Fixes rust-lang/rust#138936
cc `@scottmcm` `@dianqk`

Author: bors