RFR 9: 8074818: Resolve disabled warnings for libjava

[Roger Riggs]

Please review these native code and build changes to clear compilation 
warnings.
Most are due to mixing unsigned types with signed types or providing
the correct type to an invoked function.
Webrev:
http://bussund0416.us.oracle.com/~rriggs/webrev/webrev-fix-all-warnings-8074818/

Issues:
    8074818: Resolve disabled warnings for libjava
    8080007: Stop ignoring warnings for libjava

JPRT in progress for product and fastdebug builds on solaris, linux, 
macosx, windows,
and embedded.

Thanks, Roger