clippy: fix pedantic warnings and run clippy::pedantic lints on the codebase.

Turn on pedantic lints in dogfood and base tests.

needless_bool: fix clippy::items-after-statements
redundant_pattern_matching: fix clippy::similar-names
mods.rs: fix clippy::explicit-iter-loop
returns.rs: allow clippy::cast-possible-wrap

Fixes #3172

clippy_dev/src/lib.rs

@@ -8,7 +8,6 @@
 // except according to those terms.
 
 
-
 #![allow(clippy::default_hash_types)]
 
 use itertools::Itertools;