In order to make the code trimming-compatible, a slight behavior change was made. The SetupJSContinuation method will only get the Result of Task<TResult> objects. If an object derives from the base Task class, and defines its own Result property, SetupJSContinuation will no longer respect that property.

This was done so the behavior remains consistent between trimmed and untrimmed applications.

Contributes to dotnet#45623