Follow-up to #6971

For a property like the following:

[Experimental("RSEXPERIMENTAL001")]
public abstract bool DisableNullableAnalysis { get; }

The following symbol string is generated:

abstract Microsoft.CodeAnalysis.SemanticModel.DisableNullableAnalysis.get -> bool

But I expected the accessor to "inherit" the experimental designation on the containing property, e.g.:

[RSEXPERIMENTAL001]abstract Microsoft.CodeAnalysis.SemanticModel.DisableNullableAnalysis.get -> bool

cc @sharwell @jcouv