* ext/win32ole/win32ole_variant.c (ole_val2variant_err,
  ole_val2variantdata, Init_win32ole_variant): support VT_ERROR
  variant with error code. add WIN32OLE_VARIANT::NoParam.
* test/win32ole/test_win32ole_variant.rb(test_c_noparam,
  test_vt_error_noparam): ditto.
* ext/win32ole/win32ole.c: ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47432 b2dd03c8-39d4-4d8f-98ff-823fe69b080e