Add thread pool class

Added a thread pool class loosely based on google3 code.

Modified the compiler to have a single thread pool instead of creating new threads in ForAll.

Moved barrier to be in top level directory as it is not GC specific code.

Performance Timings:

boot.oat: 14.306596s
time mm oat-target:
real    2m33.748s
user    10m23.190s
sys 5m54.140s

Thread pool:
boot.oat: 13.111049s
time mm oat-target:
real    2m29.372s
user    10m3.130s
sys 5m46.290s

The speed increase is probably just noise.

Change-Id: If3c1280cbaa4c7e4361127d064ac744ea12cdf49
18 files changed
tree: 1d69558732c0c916e51a530985a26d4235ef0e6c
  1. .gitignore
  3. build/
  4. jdwpspy/
  5. src/
  6. test/
  7. tools/