request for review (m) - 7121618

[Jon Masamitsu]

This changes the type used for the number of GC threads to unsigned int from
mostly size_t and changes corresponding variables that take the number of GC
threads also to unsigned int.  Some variables names were also changed in
the process (principally "int i" in the work() method where "i" refers to
the thread to "uint worker_id").

There are many changes but all are straightforward type or
name changes.

7121618: Change type of number of GC workers to unsigned int.

http://cr.openjdk.java.net/~jmasa/7121618/webrev.00/

Thanks.