8169703: G1 crashes with guarantee(pretouch_gang != NULL) failed: No pretouch gang specified
Summary: Allow use of AlwaysPreTouch without passing a WorkGang.
Reviewed-by: kbarrett, dfazunen, ddmitriev

8165858: heapRegionManager is missing volatile specifier for _claims.
Summary: Added volatile specifier.
Reviewed-by: kbarrett, tschatzl

8157952: Parallelize Memory Pretouch
Summary: Use multiple threads to pretouch memory using -XX:+AlwaysPreTouch to use more memory bandwidth
Reviewed-by: jmasa, sangheki

8141501: Problems with BitMap buffer management
Reviewed-by: pliden, kbarrett

8139867: Change how startsHumongous and continuesHumongous regions work in G1.
Reviewed-by: tschatzl, tbenson

8131734: assert(!is_null(v)) failed: narrow klass value can never be zero with -Xshared:auto
Summary: Handle shared string mapping failures.
Reviewed-by: tschatzl, kbarrett, ddmitriev, hseigel
Contributed-by: tom.benson@oracle.com, jiangli.zhou@oracle.com

8042668: GC Support for shared heap ranges in CDS
Summary: Added "Archive Region" support to the G1 GC
Reviewed-by: tschatzl, brutisso
Contributed-by: tom.benson@oracle.com

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