private static boolean isAllZerosUntilEOF(BinaryReader reader) throws IOException {
		reader = reader.clone();
		while (reader.hasNext()) {
			if (reader.readNextByte() != 0) {
				return false;
			}
		}
		return true;
	}
Read a variable-length length value from the stream.
<p>
The length value will either occupy 4 (int32) or 12 bytes (int32 flag + int64 length) and
as a side-effect signals the size integer values occupy.

@param reader {@link BinaryReader} stream to read from
@param defaultPointerSize size in bytes of pointers in the program 
@return new {@link DWARFLengthValue}, or null if the stream was just zero-padded data
@throws IOException if io error
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFLengthValue.java