Sync-method syntax support

[0xF6]

• [x] Proposed
• [ ] Triage: Completed
• [ ] Prototype: not started
• [ ] Implementation: not started
• [ ] Specification: not started

define sync in method declaration

public class Foo
{
   public sync fn(): void 
   { } 
}

Ishtar view (transformation result)

// non-static variant
public class Foo
{
   public fn(): void 
   { 
        Synchronicity.For(this);
        try
        {
            // ...
        }
        finally
        {
            Synchronicity.Release(this);
        }
   } 
}
// static variant
public static class Foo
{
   private static guarder: Object = new Object();
   public static fn(): void 
   { 
        Synchronicity.For(guarder);
        try
        { 
            // ...
        }
        finally
        {
            Synchronicity.Release(guarder);
        }
   } 
}