Prefer RuntimeHelpers.Equals before notifying

[JohanLarsson]

https://docs.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.runtimehelpers.equals?view=netframework-4.8
Does it box for value types or does it get special IL? /cc @jnm2

[jnm2]

It does box. Unfortunately, there's no way to tell whether EqualityComparer<T>.Default.Equals would behave the same as RuntimeHelpers.Equals.

[jnm2]

I don't expect that to be a problem in the apps I'm thinking of. But if we want to come up with one pattern to rule them all, maybe it's best to set unconditionally and use EqualityComparer<T>.Default.Equals to determine whether to raise PropertyChanged?

[JohanLarsson]

We can make it configurable via multiple IDs. Not the most ergonomic way but it is either that of write something to editorconfig.