[X86] When checking the bits in cpu_features for function multiversioning dispatcher...

[X86] When checking the bits in cpu_features for function multiversioning dispatcher in the resolver, make sure all the required bits are set. Not just one of them

Summary:
The multiversioning code repurposed the code from __builtin_cpu_supports for checking if a single feature is enabled. That code essentially performed (_cpu_features & (1 << C)) != 0. But with the multiversioning path, the mask is no longer guaranteed to be a power of 2. So we return true anytime any one of the bits in the mask is set not just all of the bits.

The correct check is (_cpu_features & mask) == mask

Reviewers: erichkeane, echristo

Reviewed By: echristo

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D53460

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@344824 91177308-0d34-0410-b5e6-96231b3b80d8