Pls review 7091417: recvfrom's 6th input should be of type socklen_t (M)

[Paul Hohensee]

This is actually a bit broader scope than the Summary suggests, in that 
it takes into
account the possibility that socklen_t might not be the same bit width as
int and jint (which latter two are assumed synonymous in the jvm).  I spent
a bit of time with socket.h on linux/bsd/solaris to verify the actual 
argument
types of the socket methods used by the jvm.  I changed the os methods
so that their formal argument types match socket.h and put that adapter
code in jvm.cpp so as to have only a single copy of it.

Webrev here

http://cr.openjdk.java.net/~phh/7091417.00/

Thanks,

Paul