Normalize projections under binders

[jackh726]

Fixes #70243
Fixes #70120
Fixes #62529
Fixes #87219

Issues to followup on after (probably fixed, but no test added here):
#76956
#56556
#79207
#85636

r? @nikomatsakis

[jackh726]

Looks like:

• Some cleanup in the pretty code needed
• Overflow evaluating a couple tests; one never finished, the other regresses on diagnostic
• Being able to normalize earlier leads to some errors that would happen later being suppressed; this is probably fine.

Overall though, I think this is close.

[jackh726]

I got bored of this after 6...

[smmalis37]

Will this fix #76956 as well?

[jackh726]

Will this fix #76956 as well?

Probably

[SkiFire13]

I think this also fixes #56556

[jackh726]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit c101d40e59f42ac2c15aca8cccb3b19d32591834 with merge ce300333714ca415579d146d0042b1adfa9809ab...

[bors]

☀️ Try build successful - checks-actions
Build commit: ce300333714ca415579d146d0042b1adfa9809ab (ce300333714ca415579d146d0042b1adfa9809ab)

[rust-timer]

Queued ce300333714ca415579d146d0042b1adfa9809ab with parent 657bc01, future comparison URL.

[rust-timer]

Finished benchmarking try commit (ce300333714ca415579d146d0042b1adfa9809ab): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf

[jackh726]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit a7349767432e244aca61bba7f7faba0c6ab206ac with merge eaaba9d60da06713d4f80ef5a069307b3a772d2b...

[bors]

☀️ Try build successful - checks-actions
Build commit: eaaba9d60da06713d4f80ef5a069307b3a772d2b (eaaba9d60da06713d4f80ef5a069307b3a772d2b)

[Alexendoo]

The following big list of ICEs are also fixed by this PR 👍

I haven't closed/marked any as needs-test because I'm not sure which would be considered duplicates to the already added ones

• ICE typechecking closure object with bound lifetime #63031
• broken MIR (NoSolution) in closure with a parameter whose type is an alias for a reference to an associated type #68090
• Certain uses of polymorphic lifetimes seems to trigger an internal compiler error. #79463
• Internal compiler error: compiler/rustc_trait_selection/src/traits/codegen.rs:78:17 #79628
• ICE(stable): thread 'rustc' panicked at 'called Option::unwrap() on a None value', compiler/rustc_middle/src/ty/instance.rs:434:85 #80706
• Broken MIR (and diagnostics) using Higher-Rank Trait Bounds and associated types #80956
• typecheck_ice when attempting to type check trait object with duplicate associated types #81809
• Higher-ranked function pointers implement Fn traits without enforcing necessary trait bounds to make sure the return type exists #85455
• no errors encountered even though delay_span_bug issued', compiler/rustc_errors/src/lib.rs:1023:13 #86535

[jackh726]

Thanks @Alexendoo I'll take a look :)