3 more Hotspot approval requests for b59

[Paul Hohensee]

6829234: Refix 6822407 and 6812971

Fix for a fix in the Serviceability Agent.

6837224: libsaproc.so on linux needs version of 6799141

Serviceability Agent linux build fix.

6833879: Assigning positive zero is ignored when old value is negative zero

Language correctness fix.  Low risk, since it just disables an optimization.

6833576: G1: assert illegal index, growableArray.hpp:186

G1-only fix.  Could hit the assert during fastdebug QA, could
segv in product vm if pointer arithmetic produces garbage.

Thanks,

Paul