without USE_THREADS, change extern variable for dTHR
consistent semantics for exit/die in threads
SvREFCNT_dec(curstack) in threadstart() in Thread.xs
- $@ and other magic globals:
- global pseudo-lexical pad with auto-binding for magicals
- move magicals that should be per-thread into thread.h
- sv_magic for the necessary global pad entries
Thread::Pool
more Configure support