private OmfSegmentHeader createOrFindBorlandSegment(int index, int datatype) {
		if (extraSeg == null) {
			extraSeg = new ArrayList<OmfSegmentHeader>();
		}
		while (extraSeg.size() < index) {
			extraSeg.add(null);
		}
		OmfSegmentHeader segment = extraSeg.get(index - 1);
		if (segment == null) {
			segment = new OmfSegmentHeader(index, datatype);
			extraSeg.set(index - 1, segment);
		}
		return segment;
	}
Given an index, either find an existing Borland segment, or create a new one.
Borland compilers can introduce special segments with a separate indexing
scheme. These need to be stored in a separate list, while the loader needs
to look up segments by index.
@param index is the segment index
@param datatype is the type of (new) segment
@return the corresponding OmfSegmentHeader
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/omf/omf/OmfFileHeader.java