p[] instead of p^

tests/reject/titer2.nim

@@ -0,0 +1,16 @@
+discard """
+  file: "titer2.nim"
+  msg: "internal error: not implemented: pass to var parameter"
+"""
+# Try to break the transformation pass:
+iterator iterAndZero(a: var openArray[int]): int =
+  for i in 0..len(a)-1:
+    yield a[i]
+    a[i] = 0
+
+var x = [[1, 2, 3], [4, 5, 6]]
+for y in iterAndZero(x[0]): write(stdout, $y)
+#OUT 123
+
+
+