'Convert switch statement to expression' breaks code.

[CyrusNajmabadi]

Conversion on:

                long target;
                try
                {
                    switch (origin)
                    {
                        case SeekOrigin.Begin:
                            target = offset;
                            break;

                        case SeekOrigin.Current:
                            target = checked(offset + position);
                            break;

                        case SeekOrigin.End:
                            target = checked(offset + length);
                            break;

                        default:
                            throw new ArgumentOutOfRangeException(nameof(origin));
                    }
                }
                catch (OverflowException)
                {
                    throw new ArgumentOutOfRangeException(nameof(offset));
                }

                if (target < 0)
                {
                    throw new ArgumentOutOfRangeException(nameof(offset));
                }

Produced:

                try
                {
                    var target = origin switch
                    {
                        SeekOrigin.Begin => offset,

                        SeekOrigin.Current => checked(offset + position),

                        SeekOrigin.End => checked(offset + length),

                        _ => throw new ArgumentOutOfRangeException(nameof(origin)),
                    };
                }
                catch (OverflowException)
                {
                    throw new ArgumentOutOfRangeException(nameof(offset));
                }

                if (target < 0)
                {
                    throw new ArgumentOutOfRangeException(nameof(offset));
                }

[jinujoseph]

@jasonmalinowski Is this a Duplicate of #36608

[alrz]

I think not. this is about the use after switch (should not move decl). #36608 is about the common/target type.