Auto merge of #138892 - compiler-errors:revert-ptr-ptr, r=oli-obk

Revert "Rollup merge of #136127 - WaffleLapkin:dyn_ptr_unwrap_cast, r=compiler-errors"

...not permanently tho. Just until we can land something like #138542, which will fix the underlying perf issues (rust-lang/rust#136127 (comment)). I just don't want this to land on beta and have people rely on this behavior if it'll need some reworking for it to be implemented performantly.

r? `@WaffleLapkin` or reassign -- sorry for reverting ur pr! i'm working on getting it re-landed soon :>

Author: bors