When the Java class parser began culling unused constructors, the logic for determining whether a given Java class has a no-arg constructor broke when the no-arg constructor is culled. Add an explicit field for tracking the no-arg constructor property. Change-Id: Ib68929ae1108bd6fa1fd23de1d134332eb0d97a2 Reviewed-on: https://go-review.googlesource.com/29875 Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>