Patch: merge src and gcc copies of dwarf2.h

[Tom Tromey]

>>>>> "Jakub" == Jakub Jelinek <jakub@redhat.com> writes:

Jakub> BTW, why is it <elf/dwarf2.h>, rather than just <dwarf2.h>?
Jakub> What is ELF specific on DWARF2/3/4?

I did this because that is what the src tree does.

I don't actually care where it goes.

Jakub> By putting dwarf2.h right into include/ rather than
Jakub> include/elf/, we could avoid issues with combined src+gcc
Jakub> trees.

I will start work on that.
Sorry about the mess.

Tom