fixes multiline comments

tests/parser/tmultiline_comments.nim

@@ -7,6 +7,8 @@ proc main* =
   Yay, that is so cool.
   ]##
   echo "foo bar"
+  for s in ["one", "two", #["three",]# "four"]:
+    echo s
 
 var foo #[ Test the new inline comments ]#: int = 3
 ##[ A
@@ -16,3 +18,17 @@ novel documentation comment
 ]#
 ]##
 echo $foo
+
+  #[Comment here.
+  Multiple lines
+  are not a problem.]#
+
+  #[  #[ Multiline comment in already
+     commented out code. ]#
+  proc p[T](x: T) = discard
+  ]#
+
+proc bar =
+  ##[Long documentation comment
+  here.
+  ]##