[PATCH] Add support for subsections to the ELF assembler. Fixes PR8717.

[Rafael Espíndola]

> We would in fact need two parameters (the fragment list and the
> insertion point), as we won't necessarily be able to derive the
> fragment list from the insertion point if it's at the end.

Can't you pass the insertion point with the semantics of "insert after this"?

> There are also a few places in ELFObjectWriter where we do
> need to create unparented MCFragments.
>

I don't think so, check r179124.

Cheers,
Rafael