We're not comparing with code addresses any more. Instead,
we use nil algorithm functions to mark uncomparable types.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/
151040044
//go:noescape
func memeq(a, b unsafe.Pointer, size uintptr) bool
-// Code pointers for the nohash/noequal algorithms. Used for producing better error messages.
-var nohashcode uintptr
-var noequalcode uintptr
-
// noescape hides a pointer from escape analysis. noescape is
// the identity function but escape analysis doesn't think the
// output depends on the input. noescape is inlined and currently