Fix syntax error in the QueueEvent() documentation example.

Use ".", not "->", on the object.

Closes #15881.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75636 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Compilation fix for the example in wxThread documentation.

Make MyThread a friend to allow it accessing the private fields of MyFrame.

Notice that this example still remains badly written and should be ideally
entirely redone using conditions and mutexes.

See #15881.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75637 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix wrong variable name in the example in wxVariantDataSafeArray documentation.

Closes #15882.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75638 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775