Delayed window rendering on win32 with intel GPU and OpenGL enabled

Steps to reproduce

1. Get hold of a machine running Windows and uses an Intel GPU
2. Disable cursor blinking by setting gtk-cursor-blink = 0 in settings.ini
3. Start gtk3-demo with OpenGL force-enabled: GDK_GL=always gtk3-demo
4. Open a demo that has text entry
5. Type text and observe that the entry updates with a delay of one frame. For example: Type 1234, 123 is displayed, press left arrow to move the cursor, 1234 appears with the cursor placed after the 4.

Current behavior

Window updates one frame too late with OpenGL enabled (either enabled by a GLArea in that window or by force-enabling it). Doesn't happen without OpenGL.

Expected outcome

Same behaviour as without OpenGL.

Version information

gtk 3.24.2 from MSYS2

Additional information

Windows 10 1909, Intel i5-6300U integrated GPU. People also reported identical behaviour on other systems: https://github.com/horizon-eda/horizon/issues/513