reflect: make sure to clear unusable hash/equal function

Otherwise we wind up copying the one from the prototype, which is wrong.

Also rewrite the hash/equal functions to look like the ones in Go 1.8,
mainly a matter of changing names and using arrayAt.

Change-Id: I92f5c45efb53528d87124d04bef31bdb822f16f4
Reviewed-on: https://go-review.googlesource.com/41133
Reviewed-by: Than McIntosh <thanm@google.com>
1 file changed