add test

tests/stdlib/tasserts.nim

@@ -0,0 +1,19 @@
+#[
+see also tassert2
+]#
+
+import std/asserts
+import std/strutils
+
+
+
+# line 10
+block: ## checks AST isn't transformed as it used to
+  let a = 1
+  enforce a == 1
+  try:
+    enforce a > 1
+  except CatchableError as e:
+    echo e.msg
+    assert e.msg.endsWith "tasserts.nim(15, 13) `a > 1` "
+  doAssertRaises(CatchableError): enforce a > 1