Fixed parameter validation for Delegate.CreateDelegate method. (#15196)

Author: zaytsev-victor

src/mscorlib/src/System/Delegate.cs

@@ -65,7 +65,7 @@ protected unsafe Delegate(Type target, String method)
             if (target == null)
                 throw new ArgumentNullException(nameof(target));
 
-            if (target.IsGenericType && target.ContainsGenericParameters)
+            if (target.ContainsGenericParameters)
                 throw new ArgumentException(SR.Arg_UnboundGenParam, nameof(target));
 
             if (method == null)
@@ -394,7 +394,7 @@ public static Delegate CreateDelegate(Type type, Type target, String method, boo
                 throw new ArgumentNullException(nameof(type));
             if (target == null)
                 throw new ArgumentNullException(nameof(target));
-            if (target.IsGenericType && target.ContainsGenericParameters)
+            if (target.ContainsGenericParameters)
                 throw new ArgumentException(SR.Arg_UnboundGenParam, nameof(target));
             if (method == null)
                 throw new ArgumentNullException(nameof(method));