Since https://github.com/tc39/ecma262/pull/1490, the "length" and "name"
properties of a class are defined before any static methods. This is
tested by #2057, in test/language/computed-property-names of all places.
At the same time, static methods with "name" as the name would overwrite
the original property, but retain the original property enumeration
order. This was not previously tested. In fact, the overwriting behavior
was not tested at all for the "length" property.
This commit mends both holes in test coverage.
