refactor: golf ValueDistribution/LogCounting/Asymptotic ConstantSpeed Analytic/Within

[yuanyi-350]

This PR selectively ports file-level changes from #37968.

Included files:

• Mathlib/Analysis/Complex/ValueDistribution/LogCounting/Asymptotic.lean
• Mathlib/Analysis/ConstantSpeed.lean
• Mathlib/Analysis/Analytic/Within.lean

Only these file changes are included.

No build or compile check was run intentionally.

[github-actions]

PR summary 14ec76b5f0

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

No declarations were harmed in the making of this PR! 🐙

You can run this locally as follows

## summary with just the declaration names:
./scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh contains some details about this script.

---

No changes to technical debt.

You can run this locally as

./scripts/reporting/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[yuanyi-350]

I ran a profiler comparison for the changed declarations in this PR.

Results (seconds, merge-base -> PR head):

• hasFPowerSeriesWithinOnBall_iff_exists_hasFPowerSeriesOnBall: 0.186697 -> 0.175779 (-5.85%)
• analyticWithinAt_iff_exists_analyticAt': 0.051474 -> 0.033891 (-34.16%)
• one_isLittleO_logCounting_single: 0.205887 -> 0.030446 (-85.21%)
• logCounting_isBigO_one_iff_analyticOnNhd: 0.389839 -> 0.046660 (-88.03%)
• hasConstantSpeedOnWith_zero_iff: 0.100620 -> 0.045256 (-55.02%)
• unique_unit_speed_on_Icc_zero: 0.072857 -> 0.063438 (-12.93%)

Overall:

• All six changed declarations were faster on the PR head than on the merge-base version.
• The largest improvements are in Mathlib/Analysis/Complex/ValueDistribution/LogCounting/Asymptotic.lean.

Caveat:

• These are single trace.profiler runs, using the Elab.definition.value entry from lake env lean on temporary instrumented copies of the changed files.

[grunweg]

Please follow the request made in the comments here and here. Thanks!