[c2cpg] Fix handling of include paths

[max-leuthaeuser]

Paths provided via --include are now allowed to be relative to the input directory or absolute. They had to be absolute beforehand.

[maltek]

From general CLI conventions, I'd expect a relative path to be relative to the current working directory. E.g. that's how shell completion works.

Not a hard no on interpreting this relative to the input path, but it feels a bit weird to me.

[maltek]

Suggested change

	case define if define.contains("=") =>
	val split = define.split("=")
	split.head -> split(1)
	case s"$define=$value" => define -> value

[max-leuthaeuser]

From general CLI conventions, I'd expect a relative path to be relative to the current working directory. E.g. that's how shell completion works.

Did not think about that. Yeah, lets keep it that way.

[mpollmeier]

Suggested change

	val split = define.split("=")
	split.head -> split(1)
	val Array(key, value) = define.split("=")
	key -> value

IMO that's more readable, but feel free to disregard.
Note that it behaves slightly differently if there's two = in the string. My suggestion will throw a MatchError while yours will silently drop everything from the second =.