cmd/link: support trampoline insertion on ARM64

Compared to ARM32 or PPC64, ARM64 has larger range for direct jumps.
But for very large programs it can still go over the limit. Add
trampoline insertion for ARM64.

Updates #40492.

Change-Id: Id97301dbc35fb577ba3f8d5f3316a8424d4f53c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/314451


Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>