Add VMThread REPR and thread-related nqp:: ops.
Map thread related ops for MoarVM.
Add ReentrantMutex REPR and lock/unlock ops on JVM
Map lock and unlock ops on MoarVM.
beginning of a semaphore instantce
have semtryacquire return an INT, map sem{{try,}acquire,release}
confused returnval and argument types
map semacquire, semtryacquire and semrelease on moar
Add concurrent blocking queue REPR, queuepoll op.

The rest of the operations you can do on it are comfortably provided
by existing REPR operations.
Merge branch 'master' into moar-conc
Provide condition variable abstraction on JVM.
Map condition variable ops for MoarVM.
Map queuepoll op on MoarVM.
Merge branch 'master' into moar-conc
Merge branch 'moar-conc'
Bump to a MoarVM with concurrency bits.