feat: OverflowingMul trait

[enitrat]

I haven't implemented OverflowingMul for signed integers as the implementation is a bit more complex and I'm not sure about the most efficient approach yet.

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This change is 

[orizi]

Reviewed all commit messages.
Reviewable status: 0 of 5 files reviewed, 1 unresolved discussion (waiting on @enitrat)

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corelib/src/integer.cairo line 2970 at r1 (raw file):

        } else {
            (wide_result.try_into().unwrap(), false)
        }

since we are worse case based:

Suggestion:

        let MASK: u16 = BoundedInt::<u8>::max().into();
        let (v_low, _, v_with_low_masked) = u8_bitwise(wide_result, MASK);
        (v_low, v_with_low_masked != MASK)

[enitrat]

Reviewable status: 0 of 5 files reviewed, 1 unresolved discussion (waiting on @orizi)

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corelib/src/integer.cairo line 2970 at r1 (raw file):

Previously, orizi wrote…

since we are worse case based:

What are the returned values of ux_bitwise extern functions?

[orizi]

Reviewable status: 0 of 5 files reviewed, 1 unresolved discussion (waiting on @enitrat)

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corelib/src/integer.cairo line 2970 at r1 (raw file):

Previously, enitrat (Mathieu) wrote…

What are the returned values of ux_bitwise extern functions?

(and, xor, or)

[enitrat]

Reviewable status: 0 of 5 files reviewed, 1 unresolved discussion (waiting on @orizi)

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corelib/src/integer.cairo line 2970 at r1 (raw file):

Previously, orizi wrote…

(and, xor, or)

Done. Added a boyscout line documenting the biwtise libfunc.

[orizi]

Reviewed 4 of 5 files at r1, 1 of 1 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @enitrat)

a discussion (no related file):
@gilbens-starkware

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[gilbens-starkware]

Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @enitrat)