Set !captures metadata for store of &Freeze

[nikic]

When a &Freeze reference is stored (with retag), emit !captures !{!"address", !"read_provenance"} metadata to indicate that it's UB to write through the stored pointer.

Related to #146844.

r? @ghost

[nikic]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: 7070de9 (7070de944f17ba2b07a846c21112969a8504656e, parent: 3179a47d67719a92b4d3c3689aca391c40ff1a04)

[rust-timer]

Finished benchmarking commit (7070de9): comparison URL.

Overall result: ❌ regressions - 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

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.2%	[0.2%, 0.2%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 0.6%, secondary 4.7%)

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

	mean	range	count
Regressions ❌ (primary)	3.1%	[3.1%, 3.1%]	1
Regressions ❌ (secondary)	4.7%	[2.4%, 7.1%]	4
Improvements ✅ (primary)	-2.0%	[-2.0%, -2.0%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.6%	[-2.0%, 3.1%]	2

Cycles

Results (secondary -0.5%)

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)	2.0%	[2.0%, 2.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.1%, -3.1%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 515.747s -> 515.721s (-0.01%)
Artifact size: 400.75 MiB -> 400.65 MiB (-0.03%)

[nikic]

r? @RalfJung

This was originally intended to fix #146844, but that got fixed by improvements to MIR opts already (GVN presumably). It can still help in other cases where GVN won't work (e.g. address taken, or not MIR inlined), though there doesn't seem to be any interest impact visible in perf.

[rustbot]

RalfJung is not on the review rotation at the moment.
They may take a while to respond.