Improve always-returns check for CASE (fixes #422)
Improve always-returns check for CASE (fixes #422)

ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang,ghewgill/neon-lang