public static DataType getDataTypeTraceForward(Varnode vn) {
		DataType res = vn.getHigh().getDataType();
		PcodeOp op = vn.getLoneDescend();
		if (op != null && op.getOpcode() == PcodeOp.CAST) {
			Varnode otherVn = op.getOutput();
			res = MetaDataType.getMostSpecificDataType(res, otherVn.getHigh().getDataType());
		}
		return res;
	}
Get the data-type associated with a Varnode.  If the Varnode is input to a CAST p-code
op, take the most specific data-type between what it was cast from and cast to.
@param vn is the Varnode to get the data-type for
@return the data-type
Ghidra/Features/Decompiler/src/main/java/ghidra/app/decompiler/component/DecompilerUtils.java