[x86] Move the AVX v4i64 test cases down to group them together.

Increasingly I don't want to mix the integer and floating point tests,
especially with AVX where they are handled quite differently.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218233 91177308-0d34-0410-b5e6-96231b3b80d8