8048891: Remove unused JObjC from jdk repository

[Alan Bateman]

I posted a note here recently (and to macosx-port-dev) about the unused 
JObjC source code in the jdk repository [1].

I didn't see any replies or objections so I'd like to go ahead and 
remove this code. As I mentioned, this code has not been built for 
sometime and the last reference in the make files was removed early in 
JDK 9. The webrev with the proposed changes is here:

    http://cr.openjdk.java.net/~alanb/8048891/webrev/

Thanks,

Alan.

[1] http://mail.openjdk.java.net/pipermail/build-dev/2014-June/012805.html