Merging r325654:

Merging r325654:
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r325654 | ctopper | 2018-02-21 01:15:48 +0100 (Wed, 21 Feb 2018) | 10 lines

[X86] Disable CLWB for Cannon Lake

Cannon Lake does not support CLWB, therefore it
does not include all features listed under SKX anymore.

Instead, enumerate all SKX features with the exception of CLWB.

Patch by Gabor Buella

Differential Revision: https://reviews.llvm.org/D43380
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_60@325671 91177308-0d34-0410-b5e6-96231b3b80d8