Parellel mark stack processing

Enabled parallel mark stack processing by using a thread pool.

Optimized object scanning by removing dependent loads for IsClass.

Performance:
Prime: ~10% speedup of partial GC.
Nakasi: ~50% speedup of partial GC.

Change-Id: I43256a068efc47cb52d93108458ea18d4e02fccc
18 files changed
tree: c36841561a47b2ce3cf15b00fdae822e5a6c5b64
  1. build/
  2. jdwpspy/
  3. src/
  4. test/
  5. tools/
  6. .gitignore
  7. Android.mk