The ECMAScript spec defines multiple equality operations which are used
all over the spec; this patch introduces them. Of course, the two
primary equality operations are AbtractEquals ('==') and StrictEquals
('==='), which have been renamed to 'abstract_eq' and 'strict_eq' in
this patch.
In support of the two operations mentioned above, the following have
also been added: SameValue, SameValueZero, and SameValueNonNumeric.
These are important to have, because they are used elsewhere in the spec
aside from the two primary equality comparisons.
