Rollup merge of #68211 - GuillaumeGomez:add-failing-example-e0170, r=Dylan-DPC
Rollup merge of #68211 - GuillaumeGomez:add-failing-example-e0170, r=Dylan-DPC

Add failing example for E0170 explanation

r? @Dylan-DPC

graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust