Summary: Initial checkin of JSDT code
Reviewed-by: acorn, sbohne

Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold

Summary: Rewrite frame::safe_for_sender and friends to be safe for collector/analyzer
Reviewed-by: dcubed, kvn

Summary: remove old private plugin interface, simplify, rework old plugin to use unchanged Gnu sources
Reviewed-by: kvn, rasbold

Summary: incorrect encoding
Reviewed-by: kvn, rasbold, sgoldman, jrose

Summary: T_ADDRESS size is defined as 'int' size (4 bytes) but C2 use it for raw pointers and as memory type for StoreP and LoadP nodes.
Reviewed-by: jrose

Summary: Use the same default number of GC threads as used by ParNewGC and ConcMarkSweepGC (i.e., the 5/8th rule).
Reviewed-by: ysr, tonyp

Reviewed-by: jcoomes