v1.5.0-rc.0 anonymous variable in rescue clause generates compiler warning

[ianrumford]

Environment

Erlang/OTP 20 [erts-9.0] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:10] [hipe] [kernel-poll:false]

Elixir 1.5.0-rc.0 (fa0de77)

Ubuntu Xenial 16.04

Current behavior

This test code

`defmodule Misc99 do

try do
  nil
rescue
  _any -> nil
end

end
`
generates the following compiler warning:

warning: the underscored variable "_any" is used after being set. A leading underscore indicates that the value of the variable should be ignored. If this is intended please rename the variable to remove the underscore
test/misc99_test.exs:6

Expected behaviour

No warning should be given. v1.4.5 does not generate the warning.

[josevalim]

Thank you for the report!