This enables a FileArtifact implementation to specify whether its resulting file should be executable. This change also implements shebang and ELF magic checks in the file artifact.
Signed-off-by: Ophestra <cat@gensokyo.uk>
The tarArtifact predates FileArtifact pipelining. This migrates decompression and buffering into a standalone artifact implementation.
Signed-off-by: Ophestra <cat@gensokyo.uk>