[rebuid]use dynamic wrapping instead of static wrapping

StgSharp.Common/Collections/RandomAccessibleStack.cs

@@ -28,10 +28,6 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
-using System.Linq;
-using System.Runtime.CompilerServices;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace StgSharp.Collections
 {
@@ -176,7 +172,10 @@ namespace StgSharp.Collections
             Array.Resize(ref _array, newCapacity);
         }
 
-        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
 
     }
 }