Add new PlugMethodAttributes:

*RequiresPlug - Indicates that method requires a plug, and  throws a compiler exception if none exists.

*PlugNotImplemented - Method is plugged, but throws a compiler error if plug is not implemented correctly.

source/Cosmos.Core.Plugs/GCImplementionImpl.cs

@@ -21,11 +21,12 @@ namespace Cosmos.Core.Plugs
             //}
             return Heap.MemAlloc(aSize);
         }
-
+        [PlugMethod(PlugNotImplemented = true)]
         public static void IncRefCount(uint aObject)
         {
             //
         }
+        [PlugMethod(PlugNotImplemented = true)]
         public static void DecRefCount(uint aObject)
         {
             //

source/Cosmos.IL2CPU.Plugs/PlugMethodAttribute.cs

@@ -9,7 +9,8 @@ namespace Cosmos.IL2CPU.Plugs
     public Type Assembler = null;
     public bool IsMonoOnly = false;
     public bool IsMicrosoftdotNETOnly = false;
-    
+    public bool RequiresPlug = false;
+    public bool PlugNotImplemented = false;
     public bool IsWildcard = false;
     public bool WildcardMatchParameters = false;
   }

source/Cosmos.IL2CPU/GCImplementation.cs

@@ -9,23 +9,24 @@ using System.Text;
 using System.Threading;
 using System.Diagnostics;
 using Cosmos.Common;
-
+using Cosmos.IL2CPU.Plugs;
 namespace Cosmos.IL2CPU {
     [DebuggerStepThrough]
 	public static class GCImplementation {
+        [PlugMethod(RequiresPlug = true)]
 		private static void AcquireLock() {
 //			do {
 //			} while (Interlocked.CompareExchange(ref mLock, 1, 0) != 0);
             throw new NotImplementedException();
 		}
-
-		private static void ReleaseLock() {
+        [PlugMethod(RequiresPlug = true)]
+        private static void ReleaseLock() {
 //			do {
 //			} while (Interlocked.CompareExchange(ref mLock, 0, 1) != 1);
             throw new NotImplementedException();
         }
-
-		public static uint AllocNewObject(uint aSize) {
+        [PlugMethod(RequiresPlug = true)]
+        public static uint AllocNewObject(uint aSize) {
 //			uint xNewObject = RuntimeEngine.Heap_AllocNewObject(aSize + 4);
 //#if GC_DEBUG
 //			Console.Write("New Object allocated: ");
@@ -37,11 +38,12 @@ namespace Cosmos.IL2CPU {
 
 		}
 
-		/// <summary>
-		/// This function gets the pointer to the memory location of where it's stored. 
-		/// </summary>
-		/// <param name="aObject"></param>
-		public static unsafe void IncRefCount(uint aObject) {
+        /// <summary>
+        /// This function gets the pointer to the memory location of where it's stored. 
+        /// </summary>
+        /// <param name="aObject"></param>
+        [PlugMethod(RequiresPlug = true)]
+        public static unsafe void IncRefCount(uint aObject) {
 ////			if (aObject == 0) {
 ////				return;
 ////			}
@@ -77,11 +79,13 @@ namespace Cosmos.IL2CPU {
 
 		}
 
-		/// <summary>
-		/// This function gets the pointer to the memory location of where it's stored. 
-		/// </summary>
-		/// <param name="aObject"></param>
-		public static unsafe void DecRefCount(uint aObject) {
+        /// <summary>
+        /// This function gets the pointer to the memory location of where it's stored. 
+        /// </summary>
+        /// <param name="aObject"></param>
+        /// 
+        [PlugMethod(RequiresPlug = true)]
+        public static unsafe void DecRefCount(uint aObject) {
       ////			if (aObject == 0) {
       ////				return;
       ////			}