Write .note signature section when targeting FreeBSD, similar to NetBSD
and OpenBSD. This allows binaries to declare the ABI version they were
compiled for and opt out of ASLR when compiled with -race.
Fixes #48164
Change-Id: Ie54dd5c70697a3f42a75fd640540350fd8a4dc71
Reviewed-on: https://go-review.googlesource.com/c/go/+/412494 Reviewed-by: Meng Zhuo <mzh@golangcn.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Yuval Pavel Zholkover <paulzhol@gmail.com>