Replace RuntimeHelpers.CreateSpan<T>(LdMemberToken) with new T[] { }

[ds5678]

Problem

Resolves #3379

Solution

• Any comments on the approach taken, its consistency with surrounding code, etc.
  • I tried to make it very similar to the code for Span<T>(void*, int).
• Which part of this PR is most in need of attention/improvement?
  • Testing. I'm happy to write additional tests and modify my existing test.
• At least one test covering the code changed

[ds5678]

Sorry, I meant to come back to this. It just slipped my mind.

[ds5678]

I appreciate you working on it. If you want, I can finish things up. I saw that the CI failed for the unit test. I'll resolve that.

[ds5678]

If there's any other changes you want me to make, let me know.

[siegfriedpammer]

I have fixed some more things locally, I will try to re-integrate your recent additions as well...

[siegfriedpammer]

Thank you very much for your contribution! Sorry for the trouble!

[ds5678]

Thank you as well!