[release-branch.go1.16] cmd/link: support more load commands on Mach-O

Fixes #49923.

Change-Id: I74dd9170a51cc93ce3ec5e5860c2eb2912f081f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/312729


Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
(cherry picked from commit b6ff3c69)
Reviewed-on: https://go-review.googlesource.com/c/go/+/368835


Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Trust: Heschi Kreinick <heschi@google.com>