Add XFAIL:arm again on 4 MCJIT tests, since r194558. AArch64 has been left removed.

They are failing on clang-native-arm-cortex-a9.

Please tweak MCJIT/lit.local.cfg, if this didn't satisfy bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194561 91177308-0d34-0410-b5e6-96231b3b80d8