According to ETL page 240, a Multi_branch which has an Else_part
should have the same effect as the Compound in that Else_part if no
inspect constant matches the inspect expression (and should *not*
trigger an exception).  But a Multi_branch with an Else_part whose
Compound is empty triggers an "Unmatched inspect value" exception.

Fixed in Prerelease 93.02.17.