perf: assorted compiler annotations

[hargoniX]

This PR is based on a systematic review of all read-only operations on the default containers in core. Where sensible it applies specialize annotations on higher order operations that lack them or borrow annotations on parameters that should morally be borrowed (e.g. the container when iterating over it).

[hargoniX]

!bench

[leanprover-radar]

Benchmark results for c1c6492 against e0a29f4 are in. Significant changes detected! @hargoniX

• ✅ build//instructions: -108.3G (-0.90%)

Large changes (1✅)

• ✅ misc/leanchecker --fresh Init//instructions: -8.7G (-2.31%)

Medium changes (29✅)

Too many entries to display here. View the full report on radar instead.

Small changes (1002✅, 3🟥)

Too many entries to display here. View the full report on radar instead.

[mathlib-lean-pr-testing]

Mathlib CI status (docs):

• ❗ Mathlib CI can not be attempted yet, as the nightly-testing-2026-04-10 tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto nightly-with-mathlib, Mathlib CI should run now. You can force Mathlib CI using the force-mathlib-ci label. (2026-04-10 12:00:44)

[leanprover-bot]

Reference manual CI status:

• ❗ Reference manual CI can not be attempted yet, as the nightly-testing-2026-04-10 tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto nightly-with-manual, reference manual CI should run now. You can force reference manual CI using the force-manual-ci label. (2026-04-10 12:00:45)