cmd/compile: internal compiler error invalid heap allocated var without Heapaddr [1.25 backport]

[gopherbot]

@mauri870 requested issue #80097 to be considered for backport to the next 1.25 minor release.

@gopherbot please open backport issues

[gopherbot]

Change https://go.dev/cl/800180 mentions this issue: [release-branch.go1.25] cmd/compile: don't require Heapaddr for heap vars in dead code