addZoirErrorMessages

    pub fn addZoirErrorMessages(
        eb: *ErrorBundle.Wip,
        zoir: std.zig.Zoir,
        tree: std.zig.Ast,
        source: [:0]const u8,
        src_path: []const u8,
    ) !void {
        assert(zoir.hasCompileErrors());

        for (zoir.compile_errors) |err| {
            const err_span: std.zig.Ast.Span = span: {
                if (err.token.unwrap()) |token| {
                    const token_start = tree.tokenStart(token);
                    const start = token_start + err.node_or_offset;
                    const end = token_start + @as(u32, @intCast(tree.tokenSlice(token).len));
                    break :span .{ .start = start, .end = end, .main = start };
                } else {
                    break :span tree.nodeToSpan(@fromBackingInt(@intCast(err.node_or_offset)));
                }
            };
            const err_loc = std.zig.findLineColumn(source, err_span.main);

            try eb.addRootErrorMessage(.{
                .msg = try eb.addString(err.msg.get(zoir)),
                .src_loc = try eb.addSourceLocation(.{
                    .src_path = try eb.addString(src_path),
                    .span_start = err_span.start,
                    .span_main = err_span.main,
                    .span_end = err_span.end,
                    .line = @intCast(err_loc.line),
                    .column = @intCast(err_loc.column),
                    .source_line = try eb.addString(err_loc.source_line),
                }),
                .notes_len = err.note_count,
            });

            const notes_start = try eb.reserveNotes(err.note_count);
            for (notes_start.., err.first_note.., 0..err.note_count) |eb_note_idx, zoir_note_idx, _| {
                const note = zoir.error_notes[zoir_note_idx];
                const note_span: std.zig.Ast.Span = span: {
                    if (note.token.unwrap()) |token| {
                        const token_start = tree.tokenStart(token);
                        const start = token_start + note.node_or_offset;
                        const end = token_start + @as(u32, @intCast(tree.tokenSlice(token).len));
                        break :span .{ .start = start, .end = end, .main = start };
                    } else {
                        break :span tree.nodeToSpan(@fromBackingInt(@intCast(note.node_or_offset)));
                    }
                };
                const note_loc = std.zig.findLineColumn(source, note_span.main);

                // This line can cause `wip.extra.items` to be resized.
                const note_index = @backingInt(try eb.addErrorMessage(.{
                    .msg = try eb.addString(note.msg.get(zoir)),
                    .src_loc = try eb.addSourceLocation(.{
                        .src_path = try eb.addString(src_path),
                        .span_start = note_span.start,
                        .span_main = note_span.main,
                        .span_end = note_span.end,
                        .line = @intCast(note_loc.line),
                        .column = @intCast(note_loc.column),
                        .source_line = if (note_loc.eql(err_loc))
                            0
                        else
                            try eb.addString(note_loc.source_line),
                    }),
                    .notes_len = 0,
                }));
                eb.extra.items[eb_note_idx] = note_index;
            }
        }
    }