cmd/internal/obj/x86: don't apply workaround for solaris to darwin
cmd/internal/obj/x86: don't apply workaround for solaris to darwin

Currently, we have a workaround for solaris that enforce aboslute
addressing for external symbols. However, We don't want to use the
workaround for darwin.
This CL also refactors code a little bit, because the original function
name is not appropriate now.

Updates #17490

Change-Id: Id21f9cdf33dca6a40647226be49010c2c324ee24
Reviewed-on: https://go-review.googlesource.com/54871
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

polyverse-security/go,akutz/go,CAFxX/go,Cofyc/go,codestation/go,polyverse-security/go,codestation/go,akutz/go,akutz/go,polyverse-security/go,nawawi/go,cloudflare/go,nawawi/go,golang/go,golang/go,CAFxX/go,nawawi/go,josharian/go,CAFxX/go,Cofyc/go,polyverse-security/go,CAFxX/go,akutz/go,josharian/go,CAFxX/go,josharian/go,golang/go,Cofyc/go,cloudflare/go,golang/go,Cofyc/go,nawawi/go,christopher-henderson/Go,CAFxX/go,nawawi/go,akutz/go,golang/go,codestation/go,cloudflare/go,golang/go,cloudflare/go,CAFxX/go,Cofyc/go,josharian/go,nawawi/go,Cofyc/go,golang/go,nawawi/go,cloudflare/go,golang/go,josharian/go,Cofyc/go,codestation/go,polyverse-security/go,polyverse-security/go,akutz/go,cloudflare/go,codestation/go,Cofyc/go,polyverse-security/go,akutz/go,CAFxX/go,josharian/go,cloudflare/go,josharian/go,josharian/go,polyverse-security/go,nawawi/go,codestation/go,akutz/go,codestation/go,cloudflare/go,codestation/go