Auto merge of #114774 - Enselic:less-move-size-noise, r=oli-obk

Avoid duplicate `large_assignments` lints

By checking for overlapping spans.

This PR does the "reduce noisiness" task in #83518.

r? `@oli-obk` who added E-mentor and E-help-wanted and wrote the initial code.

(The fix itself is in rust-lang/rust@dc82736. The two commits before that are just small refactorings.)

Author: bors