This reverts commit e7568b68da and relands
c6f7b720ec.
The culprit was: missed that libc also had a dependency on one of the
copies of `google-benchmark`
Also opportunistically fixed indentation from prev. change.
Differential Revision: https://reviews.llvm.org/D112012
under third-party
This change:
- moves the libcxx copy of `google/benchmark` to
`third-party/benchmkark`
- points the 2 uses of the library (libcxx and llvm/utils) to this copy
We picked the licxx copy because it is the most up to date.
Differential Revision: https://reviews.llvm.org/D112012