CORE-13582 Regression: [WIN32K] reproducable BSOD due to unhandled exception - UltraVNC 1.2.1.1 local loopback connection

Regression-Test:

r75390 BSOD 0x0000001e
r75320 BSOD 0x0000001e
r75294 BSOD 0x0000001e
r75293 BSOD 0x0000001e	GUILTY!
r75292 working
r75263 working
r75210 working
r75100 working
r75060 working