[PATCH][AArch64] Add support for vget/vset_lane_f16 ACLE functions

[Tim Northover]

Hi Chad,

> According to the latest documentation I have the ACLE prototypes for
> vget/vset_lane_f16 are:
>
> float16_t vget_lane_f16(float16x4_t v, const int lane)

My interpretation has always been that the prototypes and calling
conventions of the intrinsics themselves are merely notional. If the
program ever gets into the state of having to call one of them,
something has gone horribly wrong. They indicate the type-checking
desired of a compiler, but not much else (and that's QoI).

That said, it appears the online ACLE I was referring to does date
from 2011. Do you have a more recent one, and does it promote __fp16
to a more first-class status?

If not, the usual approach would be to implement these particular
intrinsics in terms of some macro expansion so that calling
conventions don't come into it.

Cheers.

Tim.