Work around 2.086 bugs

source/tanya/container/array.d

@@ -306,8 +306,13 @@ struct Array(T)
      */
     ~this()
     {
-        clear();
-        (() @trusted => allocator.deallocate(slice(capacity)))();
+        destroyAll(slice(this.length_));
+        deallocate();
+    }
+
+    private void deallocate() @trusted
+    {
+        allocator.deallocate(slice(capacity));
     }
 
     static if (isCopyable!T)
@@ -456,7 +461,7 @@ struct Array(T)
                     destroy(*src);
                 }
             }
-            allocator.deallocate(this.data[0 .. this.capacity_]);
+            deallocate();
             this.data = cast(T*) buf;
         }
         this.capacity_ = size;

source/tanya/container/entry.d

@@ -116,7 +116,7 @@ package static immutable size_t[33] primes = [
     805306457, 1610612741, 3221225473
 ];
 
-package struct HashArray(alias hasher, K, V = void)
+package(tanya.container) struct HashArray(alias hasher, K, V = void)
 {
     alias Key = K;
     alias Value = V;

source/tanya/container/list.d

@@ -978,10 +978,12 @@ struct DList(T)
     // 0th and the last elements of the list.
     private Entry* head, tail;
 
-    invariant ((this.tail is null && this.head is null)
-            || (this.tail !is null && this.head !is null));
-    invariant (this.tail is null || this.tail.next is null);
-    invariant (this.head is null || this.head.prev is null);
+    static if (__VERSION__ < 2086) // Bug #20171.
+    {
+        invariant ((this.tail is null) == (this.head is null));
+        invariant (this.tail is null || this.tail.next is null);
+        invariant (this.head is null || this.head.prev is null);
+    }
 
     /**
      * Creates a new $(D_PSYMBOL DList) with the elements from a static array.