This the initial commit for adding a thread pool to the Dart
server. For now it is hidden behind a flag (--enable_thread_pool)
and when enabled just starts up and processes 100 void tasks.
Mac OS implementation is not tested and Windows implementation is
still pending.
As we are currently not sharing anything between bin/ and vm/ I
have just used pthread calls directly in the Linux and Mac OS
implementation code. However with Monitor and Thread classes from
vm/ the thread pool could be written platform independently. This
can always be changed later.
R=ager@google.com
BUG=
TEST=
Review URL: http://codereview.chromium.org//8983017
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@2946 260f80e4-7a28-3924-810f-c04153c831b5