Add initial impl of check_pat() for UnusedParens

This uses a copied version of `check_unused_parens_expr` that is
specific to `ast::Pat`. `check_unused_parens_` could possibly be made
more generic to work with any `ast::*` that has `node` and `span`
fields.

This also only checks for the case of parens around the wildcard
pattern. It covers the case highlighted in the issue, but could check
for a lot more.

0 files changed, 0 insertions, 0 deletions