Return value type fields in registers

[Roland Westrelin]

>> With my patch and
>> -Dvalhalla.enableValueLambdaForms=true, everything else seems to work
>> fine.
>
> Right but then you need to add this switch to the ValueTypeTestBench, right?

Or change the default to true?

Running with -Dvalhalla.enableValueLambdaForms=true currently causes
some assert failures. My patch fixes them so I don't see why we would
need to keep it off.

Roland.