Own getTime on a Date instance is ignored (built-in wins over own property) #11493

Found while working on #11491. It reproduces on main.

An own getTime property defined on a Date instance (d.getTime = () => 42) is ignored: d.getTime() returns the built-in result (0 in the probe) instead of calling the own method. Node calls the own method.

This is the same family as #10943 / #10958 ("an own property beats a builtin"), which covered Map/Set/RegExp/Date/Array but apparently misses this Date method path.