8033552: Fix missing missing volatile specifiers in CAS operations in GC code
Summary: Add missing volatile specifiers.
Reviewed-by: kbarrett, tschatzl

8157907: Incorrect inclusion of atomic.hpp instead of atomic.inline.hpp
Summary: Remove atomic.inline.hpp and move the contents back into atomic.hpp
Reviewed-by: stefank, pliden, simonis

8047328: Improve memory usage for cards in SparsePRTEntry
Summary: Use uint16_t for cards in a SparsePRTEntry, and use an additional integer to record the current position on where to add the next card.
Reviewed-by: mgerdin, ehelin
Contributed-by: Andreas Sjoberg <andreas.sjoberg@oracle.com>, Thomas Schatzl <thomas.schatzl@oracle.com>

8155721: Sparse remset wastes half of entry memory
Summary: Only allocate as much SparsePRTEntry memory as required, not for the theoretical maximum.
Reviewed-by: mgerdin, sjohanss

8141045: Remove SPARSE_PRT_VERBOSE from the G1 code
Reviewed-by: tschatzl, kbarrett

8047330: Remove unrolled card loops in G1 SparsePRTEntry
Reviewed-by: ehelin, mgerdin, tschatzl
Contributed-by: andreas.sjoberg@oracle.com

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