chore: lean --stats gives number of imported bytes

[Kha]

Thanks to mmap, startup time is not necessarily related to this figure, but it can be used as a rough measure for that and how much data the module depends on, i.e. the rebuild chance.

Also adds new cumulative benchmarks for this metric as well as the number of imported constants and env ext entries.

[Kha]

!bench

[leanprover-bot]

Here are the benchmark results for commit b67e2f7.
There were significant changes against commit 0002ea8:

  Benchmark                            Metric       Change
  =================================================================
- Std.Data.Internal.List.Associative   task-clock     4.6% (35.5 σ)
- Std.Data.Internal.List.Associative   wall-clock     4.8% (25.6 σ)
- bv_decide_mod                        task-clock     2.7% (25.9 σ)
- bv_decide_mod                        wall-clock     2.8% (32.6 σ)
- parser                               task-clock     6.4% (27.6 σ)
- parser                               wall-clock     6.4% (27.5 σ)

[leanprover-community-bot]

Mathlib CI status (docs):

• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase 0002ea8a3702a0c2191b03e1274aefc05b53ca8c --onto 0a9c24649767dea857a388e5385b7ae94bfd0185. You can force Mathlib CI using the force-mathlib-ci label. (2025-06-11 16:43:11)

[Kha]

!bench

[leanprover-bot]

Here are the benchmark results for commit 0e09804.
There were significant changes against commit 0002ea8:

  Benchmark                         Metric                  Change
  ==========================================================================
- Init.Data.BitVec.Lemmas re-elab   branch-misses             1.2%  (31.5 σ)
- rbmap_library                     task-clock                6.8%  (26.9 σ)
- rbmap_library                     wall-clock                6.7%  (24.1 σ)
- stdlib                            blocked (unaccounted)     1.3% (132.7 σ)