patch applied (ghc): handle ThreadMigrating in throwTo() (#4811)

[Simon Marlow]

Fri Dec  3 01:48:18 PST 2010  Simon Marlow <marlowsd at gmail.com>
  * handle ThreadMigrating in throwTo() (#4811)
  If a throwTo targets a thread that has just been created with
  forkOnIO, then it is possible the exception strikes while the thread
  is still in the process of migrating.  throwTo() didn't handle this
  case, but it's fairly straightforward.

    M ./rts/RaiseAsync.c +12

View patch online:
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=ghc;a=darcs_commitdiff;h=20101203094818-12142-c3aee155887fc0b41ac517101107dad1a1434b23.gz