fixes #304

tests/compile/thygienictempl.nim

@@ -8,3 +8,11 @@ template t() = echo(foo)
 
 var foo = 12
 t()
+
+
+template test_in(a, b, c: expr): bool {.immediate, dirty.} =
+  var result {.gensym.}: bool = false
+  false
+
+when isMainModule:
+  assert test_in(ret2, "test", str_val)