8168774: Polymorhic signature method check crashes javac
Summary: Check for polysig method assumes arity is greater than zero
Reviewed-by: vromero
ConditionalWithVoid.java:12:71: compiler.err.void.not.allowed.here
ConditionalWithVoid.java:14:30: compiler.err.neither.conditional.subtype: java.lang.Integer, void
2 errors