8146991: Introduce per-worker preserved mark stacks in ParallelGC
Reviewed-by: tschatzl, ysr

8146395: Add inline qualifier in oop.hpp and fix inlining in gc files
Summary: Fix remaining issues after 8146401. Also fix windows VS2010 linkage problem (g1OopClosures.hpp).
Reviewed-by: stefank, mgerdin

8079792: GC directory structure cleanup
Reviewed-by: brutisso, stefank, david