[cPerf] LNT error on LLD bot

[Renato Golin via llvm-commits]

Now I remember why we don't have GCC on that machine...

http://lab.llvm.org:8011/builders/clang-cmake-aarch64-lld/builds/1100/steps/cmake%20stage%201/logs/stdio

CMake Error at cmake/modules/HandleLLVMOptions.cmake:189 (message):
  Host compiler does not support '-fuse-ld=lld'

We may need to re-think this strategy, but before that, we need to
revert whatever made it break, even if that wasn't the real thing, to
get the bots green again.

--renato