fixed #634 : ZSTDMT_compressCCtx() doesn't provide frame content size in header
fixed #634 : ZSTDMT_compressCCtx() doesn't provide frame content size in header

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