Currently, if either argument is number, the result is never. Instead, the result should be boolean.

In #1357, the following example is being added to GreaterThan's doc:

declare function setPositive<N extends number>(value: GreaterThan<N, 0> extends true ? N : never): void;

But this function can be called with a negative number if the type of the parameter is number, like:

setPositive(-1 as number); // Works

Because currently GreaterThan<number> returns never and never extends true.

Changing GreaterThan<number> to return boolean prevents this because boolean doesn't extend true. And in case you wanted to allow the number type, you could simply do true extends GreaterThan<N, 0> instead of GreaterThan<N, 0> extends true.

This PR also applies similar fix to LessThan, GreaterThanOrEqual and LessThanOrEqual.