Fix assertions for native functions returning arrays

[Daniel-Cortez]

What this PR does / why we need it:

Fixes two assertions triggering when a native function explicitly returning an array gets defined or called (see #466).

Which issue(s) this PR fixes:

Fixes #466

What kind of pull this is:

• [x] A Bug Fix
• [ ] A New Feature
• [ ] Some repository meta (documentation, etc)
• [ ] Other

Additional Documentation:

Special thanks to @IllidanS4 not only for reporting the bug this PR fixes, but also for making a thorough research for the source of the said bug, which made the overall process of fixing it much easier.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity.

[Y-Less]

Merged locally.