cmd/compile: internal compiler error: panic: runtime error: index out of range [0] with length 0 [1.18 backport]

[gopherbot]

@mdempsky requested issue #51765 to be considered for backport to the next 1.18 minor release.

@gopherbot please backport to Go 1.18; this is a compiler bug that could theoretically lead to silent miscompilation of valid user code

[gopherbot]

Change https://go.dev/cl/394296 mentions this issue: [release-branch.go1.18] cmd/compile: replace Type.OrigSym with Type.OrigType

[toothrot]

Approved. This is a serious issue with no workaround.

[gopherbot]

Closed by merging 78b8b4a to release-branch.go1.18.