[ARM64] Disable regression tests for the old JIT.

Since the ARM64 backend doesn't implement support for the old JIT those tests are failing when the regression tests are run on an AArch64 host.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207530 91177308-0d34-0410-b5e6-96231b3b80d8