Rollup merge of #116995 - estebank:issue-69944, r=compiler-errors

Point at assoc fn definition on type param divergence

When the number of type parameters in the associated function of an impl and its trait differ, we now *always* point at the trait one, even if it comes from a foreign crate. When it is local, we point at the specific params, when it is foreign, we point at the whole associated item.

Fix #69944.

Author: matthiaskrgr