Verify that llvm can generate the prefetchw instruction when the CPU is Atom Silvermont.
Verify that llvm can generate the prefetchw instruction when the CPU is
Atom Silvermont.

Patch by Sriram Murali.



git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@190957 91177308-0d34-0410-b5e6-96231b3b80d8

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