Rollup merge of #119872 - compiler-errors:eagerly-emit-delayed-bugs, r=oli-obk,nnethercote

Give me a way to emit all the delayed bugs as errors (add `-Zeagerly-emit-delayed-bugs`)

This is probably a *better* way to inspect all the delayed bugs in a program that what exists currently (and therefore makes it very easy to choose the right number `N` with `-Zemit-err-as-bug=N`, though I guess the naming is a bit ironic when you pair both of the flags together, but that feels like naming bikeshed more than anything).

This pacifies my only concern with rust-lang/rust#119871 (comment), because (afaict?) that PR doesn't allow you to intercept a delayed bug's stack trace anymore, which as someone who debugs the compiler a lot, is something that I can *promise* that I do.

r? `@nnethercote` or `@oli-obk`

Author: GuillaumeGomez