Re: expected test failures in t/pmc, t/run, and t/stm

[Allison Randal]

Thanks all for the reports. I see two common trouble spots in hellgrind 
and the test output. One is a possible race condition if two threads add 
tasks to the concurrency scheduler at exactly the same moment. The other 
is the fact that PCC uses globals in the interpreter to store invocation 
information, so code for a particular interpreter (event handlers, 
callbacks, etc) must always be executed within that interpreter's runloop.

Both are addressed by PDD 25, so I'll work on implementing those pieces. 
(The current implementation is partial, enough to support PDD 24.)

More later,
Allison