Win32: resolve some symbols re-definition of windows.h in glfw3native.h (#2643)
* Win32: resolve some symbols re-definition of windows.h in glfw3native.h
This reflects GLFW's fix: https://github.com/glfw/glfw/issues/1348
This enables to build with a external GLFW containing the
following fix:
* https://github.com/glfw/glfw/commit/05f6c13d119ea2662c97527d2421fb4cffd3dbfc
Currently, glfw3native.h of the internal GLFW is customized at
https://github.com/raysan5/raylib/commit/2feea87b616292b5bce4454a42c2d048f1cce7d8
This fix is compatible with the current customized glfw3native.h.
This fix enables us to update it to the latest and remove the
customization.
* Win32: remove unneeded typedef