Struct dmd.tocvdebug.CvFieldList
Helper struct for field list records LF_FIELDLIST/LF_FIELDLIST_V2
struct CvFieldList;
if the size exceeds the maximum length of a record, the last entry is an LF_INDEX entry with the type index pointing to the next field list record
Processing is done in two phases:
Phase 1: computing the size of the field list and distributing it over multiple records - construct CvFieldList with some precalculated field count/length - for each field, call count(length of field)
Phase 2: write the actual data - call alloc() to allocate debtyp's - for each field, - call writePtr() to get a pointer into the current debtyp - fill memory with field data - call written(length of field) - call debtyp() to create type records and return the index of the first one