Raise instead of crashing on when trying to use list operators in guards (#10363)

Author: goalves

lib/elixir/src/elixir_utils.erl

@@ -27,9 +27,9 @@ guard_op('orelse', 2) ->
 guard_op(Op, Arity) ->
   try erl_internal:op_type(Op, Arity) of
     arith -> true;
-    list  -> true;
     comp  -> true;
     bool  -> true;
+    list  -> false;
     send  -> false
   catch
     _:_ -> false

lib/elixir/test/elixir/kernel/guard_test.exs

@@ -310,6 +310,22 @@ defmodule Kernel.GuardTest do
         end
       end
 
+      assert_raise CompileError,
+                   ~r"cannot invoke remote function :erlang\.\+\+/2 inside guards",
+                   fn ->
+                     defmodule ListSubtractionUsage do
+                       defguard foo(list) when list ++ []
+                     end
+                   end
+
+      assert_raise CompileError,
+                   ~r"cannot invoke remote function :erlang\.\-\-/2 inside guards",
+                   fn ->
+                     defmodule ListSubtractionUsage do
+                       defguard foo(list) when list -- []
+                     end
+                   end
+
       assert_raise CompileError, ~r"invalid expression in guard", fn ->
         defmodule LocalCallUsage do
           defguard foo(local, call) when local.(call)