To avoid buffer overflow when smaller FD_SETSISE is used in ext
  libraries.

* win32/win32.c (rb_w32_fdset): this function is not used anymore.
  But we leave this for compatibility.

* win32/win32.c (rb_w32_select_with_thread): fix SEGV when smaller
  FD_SETSISE is used in ext libraries. Dereference of fd_set pointer
  causes SEGV.

* test/-ext-/win32/test_fd_setsize.rb(TestFdSetSize): add tests for
  above.
* ext/-test-/win32/fd_setsize/depend: ditto.
* ext/-test-/win32/fd_setsize/extconf.rb: ditto.
* ext/-test-/win32/fd_setsize/fd_setsize.c: ditto.

  [ruby-core:44588] [Bug #6352]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e