expectSwitchSuffix

fn expectSwitchSuffix(p: *Parse, main_token: TokenIndex) !Node.Index {
    _ = try p.expectToken(.l_paren);
    const expr_node = try p.expectExpr();
    _ = try p.expectToken(.r_paren);
    _ = try p.expectToken(.l_brace);
    const cases = try p.parseSwitchProngList();
    const trailing_comma = p.tokenTag(p.tok_i - 1) == .comma;
    _ = try p.expectToken(.r_brace);

    return p.addNode(.{
        .tag = if (trailing_comma) .switch_comma else .@"switch",
        .main_token = main_token,
        .data = .{ .node_and_extra = .{
            expr_node,
            try p.addExtra(Node.SubRange{
                .start = cases.start,
                .end = cases.end,
            }),
        } },
    });
}