ref discard produces nullability warning

[stephentoub]

Version Used:
d8d7886

Steps to Reproduce:

var array = new object[1];
_ = ref array[0];

Diagnostic Id:
CS8619

Expected Behavior:
No warnings.

Actual Behavior:

warning CS8619: Nullability of reference types in value of type 'object' doesn't match target type 'object?'.

[jaredpar]

Is that from an actual code pattern or just a behavior you observed? Trying to think of reason you'd want to discard a ref access and not coming up with one

[stephentoub]

Just a behavior I observed as part of demonstrating to someone where covariance checks happen and being surprised when they didn't.