Also erase substs for new infcx in pin move error
The code originally correctly erased the regions of the type it passed to the newly created infcx. But after the `fn_sig` query was made to return an `EarlyBinder<T>`, some substs that were around were substituted there without erasing their regions. They were then passed into the newly cerated infcx, which caused the ICE.
Fixes#107419
r? compiler-errors who reviewed the original PR adding this diagnostic
5ff6cdca7e