[M3commit] [modula3/cm3] d88a3a: Fix race condition during startup.

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/modula3/cm3
  Commit: d88a3a220a92e73b8e954761e39009d499424e09
      https://github.com/modula3/cm3/commit/d88a3a220a92e73b8e954761e39009d499424e09
  Author: Jay Krell <jay.krell at cornell.edu>
  Date:   2016-07-30 (Sat, 30 Jul 2016)

  Changed paths:
    M m3-libs/m3core/src/thread/WIN32/ThreadWin32.m3

  Log Message:
  -----------
  Fix race condition during startup.
The problem with the code is subtle.
The globals are refetched after the critical section is left,
however a race still exists if many threads are created right
at startup, the overwrite of slots outside the lock can result
in preexisting threads (that were just prior created) being lost.