Change Promise properties to internal properties (#2526)

There was an issue in the Promise implementation where properties were accessible from JavaScript.
ie. `Object.defineProperty(Object.prototype, 0, {})` could modify properties which should've been inaccessible.
The reason behind that is somewhat interesting as 0-7 were the same values as the enum values in the property list of the Promise object.
Changing these properties to internal, makes them inaccessible from JS side.

Also some tests have been changed, namely 2490 and 2465.
The 2490 one got renamed, and all of the testcases from the issue have been added.
2465 got changed as well, since currently our Promise implementation can't display Promise errors, so we should check if an error is correctly returned.

Fixes #2490

Co-authored-by: Robert Fancsik <frobert@inf.u-szeged.hu>
JerryScript-DCO-1.0-Signed-off-by: Daniel Balla dballa@inf.u-szeged.hu

0 files changed, 0 insertions, 0 deletions