[vector] Intrinsics for fromByteArray, fromByteBuffer, intoByteArray, intoByteBuffer

[John Rose]

On May 2, 2018, at 7:41 PM, John Rose <john.r.rose at oracle.com> wrote:
> 
> HTH
> — John

P.S. I mentioned range checking, but didn't mention a few other
tricky bits, notably alignment checks (if relevant) and endian-ness
checks.  We don't want to ignore any of that.  We've had many
bugs in the past from assuming that someone else is worrying
about alignment and endian-ness.  There's also the "read-only"
characteristic of buffers, which a store must respect.