.Result after Task.WhenAll raise VSTHRD002

[ygalbel]

Bug description

When you have multiple tasks and you await them with await Task.WhenAll(t1, t2),
which problem can be if you call after that to t1.Result

I checked with sharplab and .Result version is smaller.

Repro steps

            Task<int> t1 = Task.FromResult(1);
            Task<int> t2 = Task.FromResult(2);

            await Task.WhenAll(t1, t2);

            var uuu = t1.Result;

Expected behavior

VSTHRD002 warning shouldn't be raised.

Actual behavior

VSTHRD002 warning is raised

• Version used:
• Application (if applicable):

Additional context

Add any other context about the problem here.