The new default return_type argument is GetOwnPropertyReturnType::All,
which returns properties with both string and symbol keys (which is also
the default for [[OwnPropertyKeys]]). This means that in some cases we
need to iterate the ordered property table twice, as we don't store
string and symbol properties separately but symbols must - there's
certainly room for (performance) improvements here. On the other hand
this makes Reflect.ownKeys() return symbol properties now :^)
Object::get_own_properties() is a bit unwieldy to use - especially as
StringOnly is about to no longer be the default value. The spec has an
abstract operation specifically for this (EnumerateObjectProperties),
so let's use that. No functionality change.
Specifically:
- Object::get_own_properties()
- Object::put_own_property()
- Object::put_own_property_by_index()
These APIs make no sense (and are inconsistent, get_own_property()
didn't have this parameter, for example) - and as expected we were
always passing in the same object we were calling the method on anyway.
