added a comment - - edited
Will be using As3zlib for this. However it needs a bit of modification, that are available here http://code.google.com/p/as3zlib/issues/detail?id=1.
The committed swc includes those changes and does not include classes:
The swc was build with the following command:
C:\flex_sdk_220.127.116.1101B\bin\compc.exe -include-sources as3zlib\src -optimize -output as3zlib\as3zlib.swc