[LLVM][Examples] Disable broken JIT + plugin tests (AIX, Sparc)
Plugins appear to be broken on AIX, CI fails. There is logic in
CMakeLists for plugins+AIX, but it was never tested before...
Note: when plugins work, also enable tests in Examples/IRTransforms.
There's no Sparc support for JIT tests, so disable the JIT tests in the
examples (copied from ExecutionEngine/lit.local.cfg).