avoids dragging in standard library

test.zig

pub fn panic(msg: []const u8) -> noreturn { @breakpoint(); while (true) {} }
comptime {
    if (@sizeOf(@typeOf(foo)) == 0) unreachable;
}

// now you can have foo be any function you'd like to play with
fn foo() {
}

// build with:
// ./zig build_obj test.zig --verbose