public static PackedEncode buildEncoder(ResourceFile sleighFile) throws IOException {
		OutputStream stream = sleighFile.getOutputStream();
		writeSlaHeader(stream);
		OutputStream compStream = new DeflaterOutputStream(stream);
		return new PackedEncode(compStream);
	}
Build the encoder for compressing and encoding a .sla file (as a stream).
The given file is opened and a header is immediately written.  The returned
encoder is ready immediately to receive the .sla elements and attributes.
@param sleighFile is the .sla file (to be created)
@return the encoder
@throws IOException for any problems opening or writing to the file
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/pcode/utils/SlaFormat.java