[lld] r238115 - [ELF] Fix lld when no unique sections is used

[Rafael Espíndola]

> It sort of got lost among the other points, but this was meant to be
> accompanied by "and if the binary is created with yaml2obj anyway, why not
> just check in the yaml?"

So, there may be a line between the two groups where yaml is the
easiest way to create a test. So lets say you are reading the code,
notice something odd and decide to try create a file that will hit an
assert. Depending on what that assert is, yaml2obj might be the tool
for the job (or llvm-mc, or an hex editor depending on the assert).

But most cases I have seen yaml2obj mentioned are for cases that
someone chanced upon a file that causes an issue and now is trying to
figure out a way to recreate it with yaml2obj. Since we will always
want to do something reasonable with that file, why not check it in?

This patch was just one such case: the patch was written fixing an
issue on a file that was trivial to create: compile a file with two
functions using -ffunction-sections -fno-unique-section-names.

Cheers,
Rafael