cmd/link: mark stacks as non-executable on freebsd
cmd/link: mark stacks as non-executable on freebsd

Fixes #48112

Change-Id: I673a5fe61171e5ba3d8ce58daac79391fb4758f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/346872
Trust: Keith Randall <8c99c3a9284e493be632950b84cd789d08ed3e9d@golang.org>
Run-TryBot: Keith Randall <8c99c3a9284e493be632950b84cd789d08ed3e9d@golang.org>
Reviewed-by: Cherry Mui <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

golang/go,golang/go,nawawi/go,nawawi/go,cloudflare/go,cloudflare/go,CAFxX/go,golang/go,nawawi/go,cloudflare/go,CAFxX/go,nawawi/go,golang/go,golang/go,cloudflare/go,cloudflare/go,cloudflare/go,golang/go,nawawi/go,golang/go,CAFxX/go,nawawi/go,golang/go,CAFxX/go,nawawi/go,CAFxX/go,cloudflare/go,nawawi/go,cloudflare/go,CAFxX/go,CAFxX/go,CAFxX/go