Rollup merge of #93175 - spastorino:negative-traits-coherence-new, r=nikomatsakis

Implement stable overlap check considering negative traits

This PR implement the new disjointness rules for overlap check described in https://rust-lang.github.io/negative-impls-initiative/explainer/coherence-check.html#new-disjointness-rules

r? ``@nikomatsakis``

diff --cc compiler/rustc_span/src/symbol.rs
Simple merge