Add test for #1149

tests/macros/tbug1149.nim

@@ -0,0 +1,20 @@
+discard """
+msg: '''a
+s
+d
+f'''
+"""
+
+type
+  Foo = object
+    s: char
+
+iterator test2(f: string): Foo =
+  for i in f:
+    yield Foo(s: i)
+
+macro test(): stmt =
+  for i in test2("asdf"):
+    echo i.s
+
+test()