new tester; all tests categorized

tests/iter/titer3.nim

@@ -0,0 +1,22 @@
+discard """
+  file: "titer3.nim"
+  output: "1231"
+"""
+
+iterator count1_3: int =
+  yield 1
+  yield 2
+  yield 3
+
+for x in count1_3():
+  write(stdout, $x)
+
+# yield inside an iterator, but not in a loop:
+iterator iter1(a: openArray[int]): int =
+  yield a[0]
+
+var x = [[1, 2, 3], [4, 5, 6]]
+for y in iter1(x[0]): write(stdout, $y)
+
+#OUT 1231
+