Auto merge of #69793 - estebank:predicate-obligations-4, r=nikomatsakis

 Maintain chain of derived obligations

When evaluating the derived obligations from super traits, maintain a
reference to the original obligation in order to give more actionable
context in the output.

Continuation (and built on) #69745, subset of #69709.

r? @eddyb

diff --cc src/librustc_trait_selection/traits/error_reporting/suggestions.rs
Simple merge

diff --cc src/librustc_typeck/astconv.rs
Simple merge