[PATCH] Simplify DWARFCompileUnit / DWARFTypeUnit constructors (NFC).

[Frederic Riss]

>>! In D5659#9, @dblaikie wrote
:> If the problem is just the number of arguments - we can wrap that in a struct and achieve the same terseness without pushing the choice down into layers that are otherwise agnostic of that detail.

It's not only about the number of arguments, I like the fact that the Unit choses the sections it needs. I find it more logical from an OO POV than having a helper in DWARFUnitSection make the choice. Ideally, I'd like to get rid of parseDWO totally and have the DWOness be a Unit type attribute (that was the point of my comment regarding the type hierarchy). I have the feeling that this commit gets us one step closer to that.

But I can see your point though, won't argue if you reject the change.

http://reviews.llvm.org/D5659