Merging r322245:

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r322245 | ctopper | 2018-01-11 02:37:59 +0100 (Thu, 11 Jan 2018) | 5 lines

[X86] Make -mavx512f imply -mfma and -mf16c in the frontend like it does in the backend.

Similarly, make -mno-fma and -mno-f16c imply -mno-avx512f.

Withou this  "-mno-sse -mavx512f" ends up with avx512f being enabled in the frontend but disabled in the backend.
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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_60@323741 91177308-0d34-0410-b5e6-96231b3b80d8