[PATCH v2 19/19 REVIEW RFC] bfd, ld: add CTF section linking

[Nick Alcock]

On 22 Jul 2019, Nick Alcock verbalised:

> This is quite complicated because the CTF section's contents depend on
> the final contents of the symtab and strtab, because it has two sections
> whose contents are shuffled to be in 1:1 correspondence with the symtab,
> and an internal strtab that gets deduplicated against the ELF strtab
> (with offsets adjusted to point into the ELF strtab instead).  It is
> also compressed if large enough, so its size depends on its contents!

This breaks gas, in that you get a CTF section that is filled with
nothing but zero bytes. (The non-ELF support also broke emission of CTF
on ELF platforms, because I dyslexically mixed up the meanings of the
words 'early' and 'late', or something like that.)

(I didn't notice the gas breakage because GCC was preferring the system
gas without my realizing it. Ah well, it's spotted now.)

Fix coming tomorrow (still have to test it and it's gone midnight here).

(this sort of thing is why I need this stuff reviewed! :) )