empty string is treated as a void type at compile-time for var args functions

[tiehuis]

const std = @import("std");

pub fn main() void {
    comptime const native_str = "";
    std.debug.warn(" {}\n", native_str);
}

Results in the following:

/home/me/local/lib/zig/std/debug/index.zig:22:23: error: compiler bug: var args can't handle void. https://github.com/zig-lang/zig/issues/557
    stderr.print(fmt, args) catch return;
                      ^
/tmp/t.zig:5:19: note: called from here
    std.debug.warn(" {}\n", native_str);

But using a non-empy string we get the expected value:

const std = @import("std");

pub fn main() void {
    comptime const native_str = "a";
    std.debug.warn(" {}\n", native_str);
}

[andrewrk]

I think this is the same problem as #557

[andrewrk]

solved by removing var args from the language in a3f6a58