Bugfix: unsafeBytes slices were getting GCed (#913)
Bugfix: unsafeBytes slices were getting GCed (#913)

There are alternative formulations of this, for instance see
	https://www.reddit.com/r/golang/comments/5zctpf/unsafe_conversion_between_strings_and_byte_slices/

The problem manifested in the returned values from unsafeBytes occasionally
being broken. It's possible that by keeping a reference to the `a` parameter
alive, the original code would still work - however, this definitely seems like
a fix.

(A cast to `[]byte(a)` looks increasingly attractive, for all that it'll
perform small allocations and copies.)
fnproject/fn,fnproject/fn,fnproject/fn