959b2c703d
adjust how closure/generator types are printed I saw `&[closure@$DIR/issue-20862.rs:2:5]` and I thought it is a slice type, because that's usually what `&[_]` is... it took me a while to realize that this is just a confusing printer and actually there's no slice. Let's use something that cannot be mistaken for a regular type.
The goal of this directory is to track the quality of MIR that is given to codegen in a standard -O condiguration.
As such, feel free to --bless whatever changes you get here, so long as doing so doesn't add substantially more MIR.