added test for ZSTD_initCStream_advanced()
added test for ZSTD_initCStream_advanced()

when params.fParams.contentSizeFlags = 1
and pledgedSrcSize = 0
then srcSize should be considered 0 (empty), and not "unknown"

Cyan4973/zstd,Majlen/zstd,Majlen/zstd,Majlen/zstd,Cyan4973/zstd,Cyan4973/zstd,Cyan4973/zstd,Cyan4973/zstd,Majlen/zstd