In the current function, we are calling 'this' function.
1. Check to see if the current function can call 'this' function, issue error if not.
2. If the current function is not the parent of 'this' function, then add
the current function to the list of siblings of 'this' function.
3. If the current function is a literal, and it's accessing an uplevel scope,
then mark it as a delegate.
Returns true if error occurs.
In the current function, we are calling 'this' function. 1. Check to see if the current function can call 'this' function, issue error if not. 2. If the current function is not the parent of 'this' function, then add the current function to the list of siblings of 'this' function. 3. If the current function is a literal, and it's accessing an uplevel scope, then mark it as a delegate. Returns true if error occurs.