CORBA35 — Missing size information for decompress()

The ZIOP body format contains the original length of the compressed
data, which is important because it allows the compressor to efficiently
allocate a buffer to uncompress it. Unfortunately, the
Compressor::decompress() operation is not given that size, meaning that
it has to guess how big the uncompressed data will be.

The original data size should be given to the decompress() operation.
One way to do that without changing the operation signature would be to
specify that the inout Buffer target sequence should have its length
pre-populated to the expected size.