protected int getDefaultSegmentFromFlat(long flat) {
		if (flat > 0xFFFFFL) {
			return 0xFFFF;
		}
		return (int) ((flat >> 4) & 0xF000);
	}
Given a flat address offset, extract the default 16-bit segment portion
@param flat is the flat offset
@return the segment value
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/address/SegmentedAddressSpace.java