Prefer inherent methods in trait object method resolution

[Jules-Bertholet]

Fixes #51402. Inherent methods on trait objects now take precedence over methods from the trait object's trait, but these last continue to take precedence over other trait impls as before.

I don't know whether this should be feature gated or insta-stable FCP, will let T-types decide that.

r? types

@rustbot label T-types A-dyn-trait

[Jules-Bertholet]

This part is not so nice… ideally this would use the inherent impl too.

View changes since the review

[oli-obk]

@bors try @rust-timer queue

and cratering it when the try job finishes, impl lgtm

[rust-bors]

☀️ Try build successful (CI)
Build commit: 8a2f6fe (8a2f6fe57adadb246778b8d41925d3dc46d468cb)
Base parent: f28ac76 (f28ac764c36004fa6a6e098d15b4016a838c13c6)

[rust-timer]

Finished benchmarking commit (8a2f6fe): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

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

Instruction count

This perf run didn't have relevant results for this metric.

Max RSS (memory usage)

Results (primary -5.9%, secondary -6.5%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-5.9%	[-5.9%, -5.9%]	1
Improvements ✅ (secondary)	-6.5%	[-10.5%, -2.6%]	2
All ❌✅ (primary)	-5.9%	[-5.9%, -5.9%]	1

Cycles

Results (secondary 3.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.9%	[3.9%, 3.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 510.446s -> 505.256s (-1.02%)
Artifact size: 353.05 MiB -> 353.51 MiB (0.13%)