✨ Add log10 and log256

[Vectorized]

Description

This PR also removes the existing revert for 0 input in log2.

@devtooligan

Actually, OZ's log10 isn't that optimal.

If you are free, help me use halmos to verify that the implementations are equivalent.

Z3 proof that oz's and solady's log10 are equivalent.

from z3 import *

def log10_oz(x):
    t = x >= 10 ** 64
    x = If(t, x / 10 ** 64, x)
    r = If(t, 64, 0)
    t = x >= 10 ** 32
    x = If(t, x / 10 ** 32, x)
    r = If(t, r + 32, r)
    t = x >= 10 ** 16
    x = If(t, x / 10 ** 16, x)
    r = If(t, r + 16, r)
    t = x >= 10 ** 8
    x = If(t, x / 10 ** 8, x)
    r = If(t, r + 8, r)
    t = x >= 10 ** 4
    x = If(t, x / 10 ** 4, x)
    r = If(t, r + 4, r)
    t = x >= 10 ** 2
    x = If(t, x / 10 ** 2, x)
    r = If(t, r + 2, r)
    t = x >= 10 ** 1
    r = If(t, r + 1, r)
    return r

def log10_solady(x):
    t = x >= 10 ** 38
    r = If(t, 38, 0)
    x = If(t, x / 10 ** 38, x)
    t = x >= 10 ** 19
    r = r + If(t, 19, 0)
    x = If(t, x / 10 ** 19, x)
    t = x >= 10 ** 10
    r = r + If(t, 10, 0)
    x = If(t, x / 10 ** 10, x)
    t = x >= 10 ** 5
    r = r + If(t, 5, 0)
    x = If(t, x / 10 ** 5, x)
    t = x >= 10 ** 3
    r = r + If(t, 3, 0)
    x = If(t, x / 10 ** 3, x)
    return r + If(x > 9, 1, 0) + If(x > 99, 1, 0)

x = Int('x')
solve(x >= 0, x < 2**256, log10_oz(x) != log10_solady(x))

Checklist

Ensure you completed all of the steps below before submitting your pull request:

• Ran forge fmt?
• Ran forge snapshot?
• Ran forge test?

Pull requests with an incomplete checklist will be thrown out.