This is drive-by fix to a number of native code warnings in the networking code.
In NET_SockaddrToInetAddress then CHECK_NULL_RETURN is used to check the return value from setInet6Address_ipaddress but the return is an int rather than a pointer. In PlainDatagramSocketImpl's mcast_join_leave then the issue is using a jbyte* when a char* is expected. In Inet6AddressImpl.c then the warning is code before declaration (the SunStudio compilers complain about that).
While looking at these warnings then I noticed that the setInet6Address_XXX functions (and one of the get functions) return a jboolean but are declared to return an int. While not wrong, it's not obvious so I changed these functions to return a jboolean.
The webrev with the proposed changes is here: http://cr.openjdk.java.net/~alanb/8034182/webrev/ -Alan.
