Enable hover for var @"foo-bar"

[FnControlOption]

For example:

var @"foo-bar" = "foo";

const Foobar = struct { @"foo \" bar": i32 };
var foobar = Foobar{ .@"foo \" bar" = 123 };

Warning: Other than that there doesn't seem to be any noticeable slowdown on my potato, I don't know what effect this has on performance... Guidance on how to benchmark this would be much appreciated!

[leecannon]

Hover works on other but not on @"foo \" bar":

pub fn main() !void {
    var t: Foobar = undefined;
    _ = t.@"foo \" bar";
    _ = t.other;
}

const Foobar = struct {
    /// Test
    @"foo \" bar": i32,

    /// Test
    other: i32,
};