Fix LLVM's handling and detection of skylake and cannonlake CPUs
Summary:
- Rename `"skylake"` == SkylakeServerProc to `"skylake-avx512"`
- Change `"skylake"` to denote SkylakeClientProc
- Fix the detection of cpu family 6 and model 94 to be
SkylakeClientProc instead of SkylakeServerProc
- Remove the `"cnl"` for CannonLake
Reviewers: craig.topper, delena
Subscribers: zansari, echristo, qcolombet, RKSimon, spatel, DavidKreitzer, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D17090
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261482
91177308-0d34-0410-b5e6-
96231b3b80d8