cmd/compile: minor cleanup -- remove dead code conditional on test
cmd/compile: minor cleanup -- remove dead code conditional on test

It would fail now if it were turned on.

Updsates #44816.

Change-Id: I19d94f0cb2dd84271f5304c796d7c81e1e64af25
Reviewed-on: https://go-review.googlesource.com/c/go/+/301270
Trust: David Chase <ae171625adc8645b8b79b7e405a6da5aba5341e0@google.com>
Run-TryBot: David Chase <ae171625adc8645b8b79b7e405a6da5aba5341e0@google.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Cherry Zhang <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>

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