Point at the definition of non-covered
Check that there are no borrow or move conflicts in
binding @ subpat patterns.
A path pattern was interpreted as a constant, not a new variable.
This caused an irrefutable match failure in e.g.
Check if a by-value binding is by-value. That is, check if the binding’s type is not
Report that a match is not exhaustive.
Checks for common cases of “catchall” patterns that may not be intended as such.
Report unreachable arms, if any.