Throw error for recursive comparison, instead of fatal (#14989)

I don't understand the rationale of fatal erroring here. It seems this should
properly unprotect the compared elements whe

Throw error for recursive comparison, instead of fatal (#14989)

I don't understand the rationale of fatal erroring here. It seems this should
properly unprotect the compared elements when returning up the stack.

Related to GH-14980

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