Bug: Returning and concatenating a zero-length array results in undefined behaviour

[MasterQ32]

The following code yields a pretty unexpected error:

comptime {
    @compileLog(wtf() ++ [0]u8{});
}
fn wtf() [0]u8 { return [0]u8 {}; }

./main.zig:4:20: error: use of undefined value here causes undefined behavior
    @compileLog(wtf() ++ [0]u8{});
                   ^
./main.zig:4:23: note: referenced here
    @compileLog(wtf() ++ [0]u8{});

when using a literal:

comptime {
    @compileLog([0]u8{} ++ [0]u8{});
}

it works as expected:

| [0]u8{}
./main.zig:5:5: error: found compile log statement
    @compileLog([0]u8{} ++ [0]u8{});
    ^

I assume it's a bug in the result location semantics that will do weird things with zero-sized return types

[Hadron67]

Seems also affects empty structs.

fn soor() struct {}{
    return .{};
}

fn hkm(comptime aaa: anytype) void {
    std.debug.print("{}\n", .{aaa});
}

pub fn main() !void {
    // ok
    const b = soor();
    hkm(b);
    // error: use of undefined value here causes undefined behavior
    hkm(comptime soor());
}