[MTE] temporarily disable memtag-stack with exceptions

unwinding through tagged frames is fixed in upstream and cherry-picked
onto Android toolchain in https://r.android.com/2251926. until then, we
can disable stack tagging for code that uses exception, so we can get
some coverage before the toolchain update.

Test: stack_tagging_helper exception_cleanup from https://r.android.com/2175188
      fails with assertion "GetTag(&y) !=
      GetTag(__builtin_frame_address(0))" as expected
Bug: 174878242
Change-Id: I1597b21f64a92874dbccb64ffebbef7bb9bf8214