feat: add SMT-LIB overflow on addition for bitvectors (uadd_overflow,sadd_overflow, uadd_overflow_eq,sadd_overflow_eq) and support theorems

[luisacicolini]

This PR adds SMT-LIB operators to detect overflow (uadd_overflow,sadd_overflow), according to the definitions here, and the theorems proving equivalence of such definitions with the BitVec library functions (uadd_overflow_eq, sadd_overflow_eq). Support theorems for these proofs are toInt_lt, le_toInt, toInd_add_toInt_lt_two_pow, neg_two_pow_le_toInd_add_toInt, bmod_two_pow_neg_iff, emod_eq_add_self_emo. A few theorems (emod_eq_add_self_emod,Nat.cast_pow,Nat.cast_ofNat) were also pulled from Mathlib.

[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 8483ac7258b84b179f3ec369df533452afdeb758 --onto d2c4471cfa4611977bf4927b5cd849df1a4272b7. (2025-01-13 14:04:32)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase 8483ac7258b84b179f3ec369df533452afdeb758 --onto e9bd9807ef7a983365df9ac55d35040d0b2d5ef2. (2025-01-14 14:29:28)
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• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase 6ebce421423445eeac59a6f4347a562897a99e8d --onto 69a73a18fbfa1fc045bfbf1c4cf93b155d4c9387. (2025-01-27 12:40:23)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase 6ebce421423445eeac59a6f4347a562897a99e8d --onto 20c616503abe5ce4253c56dbcd7766a91c675ba0. (2025-01-28 11:12:24)

[luisacicolini]

changelog-library

[kim-em]

What are your plans for adding theorems about these?

[luisacicolini]

Ideally supporting them in bvdecide - although there are some proofs missing (they're taking me more time than I expected), so I'll draft the PR for now and open it when the proofs are done!

[kim-em]

Okay! I'm happy with these definitions, and checked them against the reference, so I'm happy to click merge as soon as we're sure they are going to be used.

[tobiasgrosser]

This looks good to go from my side.

[luisacicolini]

awaiting-review