[ARM] Some FPUs do not support exception trapping, disable test

This just disables the test.

Do we want ```enableExceptions``` to throw if trapping exceptions are not available?
I could check for that in ```initialize``` by setting some exception bit and reading it back. I'm not entirely sure if that is safe in all cases but it seems glibc is also doing it: https://sourceware.org/ml/libc-ports/2012-06/msg00091.html

(There are also FPU information registers which contain this information but those are only available to the kernel and I'm not sure if /proc/cpuinfo contains the required information)