cmd/compile: ensure bloop only kept alive addressable nodes

cmd/compile: ensure bloop only kept alive addressable nodes

Fixes #76636

Change-Id: I881f88dbf62a901452c1d77e6ffca651451c7790
Reviewed-on: https://go-review.googlesource.com/c/go/+/725420
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>