[Proposal] Allow assignment operators in with expression

[acple]

Allow assignment operators in with expression when update records.
Here is an example, no descriptions needed.

public record Record(int Count, int IntValue, string? StringValue);


var myRecord = new Record(0, 100, "abc");

{
    // as-is
    var modified = myRecord with { Count = myRecord.Count + 1, IntValue = myRecord.IntValue - 1 };
}
{
    // to-be
    var modified = myRecord with { Count += 1, IntValue -= 1 };
    var modified = myRecord with { Count++, IntValue-- };
}


{
    // as-is
    var modified = myRecord with { StringValue = myRecord.StringValue is not null ? myRecord.StringValue : "XYZ" };
}
{
    // to-be
    var modified = myRecord with { StringValue ??= "XYZ" };
}

[timcassell]

#5176

[acple]

Oh I didn't find that issue, I'll check it.