bors 42dde960f9 Auto merge of - nikomatsakis:issue-54902-underscore-bound, r=tmandry
handle underscore bounds in unexpected places

Per the discussion on , I made it a hard error to use lifetime bounds in various places where they used to be permitted:

- `where Foo: Bar<'_>` for example

I also moved error reporting to HIR lowering and added `Error` variants to let us suppress downstream errors that result.

I (imo) improved the error message wording to be clearer, as well.

In the process, I fixed the ICE in .

Fixes 
Fixes 
2018-10-19 22:54:14 +00:00
..
2018-10-17 22:57:38 +02:00
2018-10-06 10:00:26 +01:00