Added GetInvocationList to System.Delegate

[MateuszKlatecki]

Description

Added method GetInvocationList to System.Delegate

Motivation and Context

• Closes System.Delegate allow to get InvocationList Home#499

How Has This Been Tested?

Tested with following code

   public delegate void TestEventHandler();

    public class Program
    {
        public static event TestEventHandler OnTest;

        static void ListMethods(TestEventHandler handler)
        {
            var delegates = handler.GetInvocationList();

            Console.WriteLine("Delegates: " + delegates.Length);
            foreach (var d in delegates)
            {
                Console.WriteLine("Method: " + d.Method.Name);
            }
        }

        public static void Method1()
        {
            Console.WriteLine("Method 1");
        }

        public static void Method2()
        {
            Console.WriteLine("Method 2");
        }

        public static void Method3()
        {
            Console.WriteLine("Method 3");
        }

        public static void Main()
        {

            Console.WriteLine("-= Test one delegate =-");
            OnTest += Method1;
            ListMethods(OnTest);

            Console.WriteLine("-= Test two delegates -=");
            OnTest += Method2;
            ListMethods(OnTest);

            Console.WriteLine("-= Test three delegates =-");
            OnTest += Method3;
            ListMethods(OnTest);

            Console.WriteLine("-= Test remove one delegate =-");
            OnTest -= Method2;
            ListMethods(OnTest);

            Console.WriteLine("-= Test anonymous delegate =-");
            OnTest += () => { Console.WriteLine("Anonymous"); };
            ListMethods(OnTest);

            Console.WriteLine("-= Invoke =-");
            OnTest?.Invoke(); 

        }
        
    }

Output

-= Test one delegate =-
Delegates: 1
Method: Method1
-= Test two delegates -=
Delegates: 2
Method: Method1
Method: Method2
-= Test three delegates =-
Delegates: 3
Method: Method1
Method: Method2
Method: Method3
-= Test remove one delegate =-
Delegates: 2
Method: Method1
Method: Method3
-= Test anonymous delegate =-
Delegates: 3
Method: Method1
Method: Method3
Method: <Main>b__7_0
-= Invoke =-
Method 1
Method 3
Anonymous

Screenshots

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

Signed-off-by: MateuszKlatecki mateusz.klatecki@gc5.pl

[nfbot]

Hi @MateuszKlatecki,

I'm nanoFramework bot.
Thank you for your contribution!

A human will be reviewing it shortly. 😉

[CLAassistant]

All committers have signed the CLA.

[josesimoes]

LGTM!