Neon code generation problems Re: ARM regression between r223766 and r223925

As expected if I replace -mpfu=neon with -mfpu=vfpv3-d16 then all the
problems go away. This means.

1. I can't build libcxxabi unwinder because of assembly problems under !neon

2. Neon codepath is not tested by the build-bots

Regards,
ismail