Rollup merge of #24072 - ebfull:explain_closure_type_err, r=pnkfelix

Also fixed bug calling .note() instead of .help()

See #24036

diff --cc src/librustc/middle/ty.rs
Simple merge

diff --cc src/librustc/session/mod.rs
Simple merge

diff --cc src/librustc_typeck/check/mod.rs
Simple merge