Adding test for extraxt sub vector load and store avx512

Change-Id: Iefcb0ec6b6aa1b530ce5358081f02e6e522a8e50

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317202 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed