rust-lang/rust — pull request #18160 by koshlo (2014-10-19 16:35:39+00:00)
Title: Fix printing negative signed literal in print_literal

Fix for issue #18091

The problem seems to be that `ast_util::int_ty_to_string` takes unsigned number, and no one adds `-` to result string. I've fixed it by putting `-` before result string using `format!`.

I've also added `test_signed_int_to_string()` to check if implementation is valid.