public AbstractIntegerDataType getPrimitiveBaseDataType() {
		// assumes proper enforcement during construction
		DataType dt = baseDataType;
		while (dt instanceof TypeDef typeDef) {
			dt = typeDef.getBaseDataType();
		}
		if (dt instanceof Enum) {
			// TODO: uncertain if we should use signed or unsigned, although size
			// is most important
			dt = AbstractIntegerDataType.getUnsignedDataType(((Enum) dt).getLength(), dataMgr);
		}
		return (AbstractIntegerDataType) dt;
	}
Get the base datatype associated with this bit-field 
(e.g., int, long, etc., or TypeDef to supported base type)
@return base data type
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/BitFieldDataType.java