Action.il

.assembly ActionTest {}

.assembly extern mscorlib
{
    .ver 4:0:0:0
    .publickeytoken = (B7 7A 5C 56 19 34 E0 89)
}

.namespace Test
{
    .class public auto ansi sealed Action extends [mscorlib]System.MulticastDelegate
    {
        // copied disassembled code of Action delegate

        .method public hidebysig specialname rtspecialname instance void .ctor(object 'object', native int 'method') runtime managed
        {
        }

        .method public hidebysig newslot virtual instance class [mscorlib]System.IAsyncResult BeginInvoke(class [mscorlib]System.AsyncCallback callback, object 'object') runtime managed
        {
        }

        .method public hidebysig newslot virtual instance void EndInvoke(class [mscorlib]System.IAsyncResult result) runtime managed
        {
        }

        .method public hidebysig newslot virtual instance void Invoke() runtime managed
        {
        }

        // Empty

        .method private hidebysig static void EmptyAction() cil managed
        {
            ret 
        }

        .method public hidebysig specialname static class Test.Action get_Empty() cil managed
        {
            ldnull 
            ldftn void Test.Action::EmptyAction()
            newobj instance void Test.Action::.ctor(object, native int)
            ret 
        }

        .property class Test.Action Empty()
        {
            .get class Test.Action Test.Action::get_Empty()
        }
    }
}

Usage.cs

Test.Action action1 = () => { };
action1();

Test.Action action2 = Test.Action.Empty;
action2();