Invalid assertion in Number::lessThan

[linusg]

At least as far as I can tell, Number::lessThan fails the assertion in step 10 for input values such as x=0, y=1 as none of steps 1-9 apply:

1. If x is NaN, return undefined.
2. If y is NaN, return undefined.
3. If x is y, return false.
4. If x is +0𝔽 and y is -0𝔽, return false.
5. If x is -0𝔽 and y is +0𝔽, return false.
6. If x is +∞𝔽, return false.
7. If y is +∞𝔽, return true.
8. If y is -∞𝔽, return false.
9. If x is -∞𝔽, return true.
10. Assert: x and y are finite and non-zero.
11. If ℝ(x) < ℝ(y), return true. Otherwise, return false.

[jmdyck]

Since ES1, the corresponding text said that the mathematical values of x and y "are both finite and not both zero". PR #2007 changed it to the current assertion.