…nst ptr and the other with mut ptr

This still doesn't handle the case entirely correctly, requiring a more
targeted approach with a better suggestion, but at least now the
suggested syntax makes *some* sense.

Co-Authored-By: matthewjasper <mjjasper1@gmail.com>

…imulacrum

Split up ptr/mod.rs in libcore...

...one with implementation detail for const ptr and the other with mut ptr

I am not sure if the "stable since 1.0.0" flags are the correct choice for the two additional mods.
Also, is it necessary for them to be "pub"? If so, there should be a good description for them.

Closes rust-lang#66891

Tweak errors for missing associated types and type parameters

* On `dyn Trait` missing associated types, provide a structured suggestion for them
* On missing type parameters, provide structured suggestion for them
* Point at trait definition when missing required type parameter
* Tweak output of E0658
* Tweak wording of E0719
* Account for `Trait1 + Trait2` case

Fix rust-lang#66380, fix rust-lang#60595. CC rust-lang#63711.

…nikomatsakis

Don't suppress move errors for union fields

closes rust-lang#66500

Fix unresolved type span inside async object

Closes rust-lang#65180
r? @estebank
It's hard to create a minimal repro for that issue, [decided](https://rust-lang.zulipchat.com/#narrow/stream/187312-wg-async-foundations/topic/meeting.202019.2E12.2E17/near/183675659) to give up finding mcve.
cc [previous take](rust-lang#65668)

Separate region inference logic from error handling better

Split out from rust-lang#67241

r? @matthewjasper

…ewjasper

`is_binding_pat`: use explicit match & include or-pats in grammar

r? @matthewjasper @nikomatsakis