6730716: nulls from two unrelated classes compare not equal
Summary: check for not-nullness after proving that types are unrelated
Reviewed-by: kvn, never
37a05a11f281b4d238e2f9e7ebb67c63f64d0e77 jdk7-b24
75fca0b0ab83ab1392e615910cea020f66535390 jdk7-b25
fb57027902e04ecafceae31a605e69b436c23d57 jdk7-b26
3e599d98875ddf919c8ea11cff9b3a99ba631a9b jdk7-b27
02e4c5348592a8d7fc2cba28bc5f8e35c0e17277 jdk7-b28
e21f4266466cd1306b176aaa08b2cd8337a9be3d jdk7-b29
b6d6877c1155621a175dccd12dc14c54f938fb8b jdk7-b30