workaround. [ruby-core:10259]

* win32/win32.c (NtInitialize): call above function.

* signal.c (sighandler): need to tell to be interrupted to main
  context when handler is installed.

* win32/win32.[ch] (rb_win32_interrupted): new function to listen
  interrupt.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_6@11855 b2dd03c8-39d4-4d8f-98ff-823fe69b080e