Fix OProfile discovery and drop bfd dependency

[ShadowsFriend]

The current implementation did not find the OProfile library. This adds a new cmake module to find OProfile and adjusts the CMakeLists.txt to take advantage of it.

[phire]

Well, I guess all of the *nix buildbots are broken.

[ShadowsFriend]

I honestly don't know. The check shouldn't hurt though, should it?

[phire]

I guess not. Just seems hacky to test the size of void* There are a few ABIs that have 32bit pointers despite being 64bit, like x32 or the ps3 (not that dolphin will ever be running on either of those platforms)

[ShadowsFriend]

I actually copied that part from obs-studio's FindZLIB.cmake because this was recommended to me as an example and it seemed reasonable to me. I can remove that part if its too hacky for you, especially considering that Dolphin is officially announced to only run on 64 bit systems.

[Sonicadvance1]

We also detect 32bit or 64bit architectures via that check in the main CMakeLists file.
There is a comment in there explaining that it'll break on x32 ABI systems and that if we start supporting that architecture then it will need to be changed.
It's currently the best way to determine what the bitness of the architecture is without adding other checks.

[phire]

We don't need to detect the bitness of the system. /lib should always point to your library, if it doesn't, you are cross compiling, and you have bigger problems and /lib64 isn't the correct place either.

The person who wrote this .cmake file was just paranoid.

[ShadowsFriend]

I just removed the bfd dependency from the CMakelists for the OProfile option because it is not needed at all. While OProfile itself depends on it, Dolphin doesn't. And there is no reason to link against a library not needed.

[phire]

@dolphin-emu-bot rebuild

[ShadowsFriend]

I squashed the three commits into one and changed the title of the PR to better reflect the current proposal.

[ShadowsFriend]

Stripped it down to the everything that is needed to find OProfile in /usr as well as in /usr/local. Additionally implemented the requested changes. Thanks for the feedback and sorry for the mess.

[Tilka]

lgtm