implements varargs[untyped]; refs #2545; to be documented

tests/typerel/tvarargsexpr.nim

@@ -1,12 +1,14 @@
 discard """
-  output: '''success'''
+  output: '''success
+true
+true'''
 """
 
 #bug #913
 
 import macros
 
-macro thirteen(args: varargs[expr]): expr = 
+macro thirteen(args: varargs[expr]): expr =
   result = newIntLitNode(13)
 
 doAssert(13==thirteen([1,2])) # works
@@ -16,3 +18,11 @@ doAssert(13==thirteen(1,[2])) # does not work
 doAssert(13==thirteen([1], 2)) # does not work
 
 echo "success"
+
+# bug #2545
+
+import macros
+macro test(e: varargs[untyped]): expr = bindSym"true"
+
+echo test(a)
+echo test(fake=90, arguments=80, also="false", possible=true)