[dev.regabi] cmd/compile: add newline to ir.Dump
[dev.regabi] cmd/compile: add newline to ir.Dump

If you do two ir.Dumps in a row, there's no newline between them.

Change-Id: I1a80dd22da68cb677eb9abd7a50571ea33584010
Reviewed-on: https://go-review.googlesource.com/c/go/+/280672
Trust: Keith Randall <8c99c3a9284e493be632950b84cd789d08ed3e9d@golang.org>
Reviewed-by: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>

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