8078561: Error message should be generated once when -source 6 is specified
Summary: Code to avoid duplicated errors about features not supported in the current source level moved to Log
Reviewed-by: jjg
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