[dev.link] cmd/link: remove special dynlinkingGo case in pclntab pass
[dev.link] cmd/link: remove special dynlinkingGo case in pclntab pass

Now that we removed the "weird thing" about runtime.etext symbol,
we can remove this special case.

Change-Id: I2e4558367758d37e898a802bcd30671c7dd6fe89
Reviewed-on: https://go-review.googlesource.com/c/go/+/240066
Run-TryBot: Cherry Zhang <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Jeremy Faller <b3f594e10a9edcf5413cf1190121d45078c62290@golang.org>

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