seq, printf: avoid integer overflow on extreme precision/exponent

[sylvestre]

Cap seq's float precision at i32::MAX (as printf already does) and reject values whose decimal exponent does not fit in i32 before the float formatters do exponent math, preventing the panic/wrap reported in #13221.

[codspeed-hq]

Merging this PR will not alter performance

✅ 331 untouched benchmarks
⏩ 46 skipped benchmarks¹

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_{Comparing sylvestre:precision (a9535f7) with main (de2e326)}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/io-errors (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/rm/many-dir-entries-vs-OOM is now passing!
Congrats! The gnu test tests/tail/pipe-f is now passing!