[bugfix] fix OrderedTable iterators (#11562)

(cherry picked from commit 3d50f7e2a1)

lib/pure/collections/tables.nim

@@ -1253,11 +1253,13 @@ proc enlarge[A, B](t: var OrderedTable[A, B]) =
     h = nxt
 
 template forAllOrderedPairs(yieldStmt: untyped) {.dirty.} =
-  var h = t.first
-  while h >= 0:
-    var nxt = t.data[h].next
-    if isFilled(t.data[h].hcode): yieldStmt
-    h = nxt
+  if t.counter > 0:
+    var h = t.first
+    while h >= 0:
+      var nxt = t.data[h].next
+      if isFilled(t.data[h].hcode):
+        yieldStmt
+      h = nxt
 
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