Bug: Chris Covell's CPUTest shows with vertical line at wrong position

[dshadoff]

CPUTest here: https://www.chrismcovell.com/CPUTest/index.html

Shows the vertical line under the left edge of the "D" on real hardware, but 3 BAT blocks (~24 pix) later on Mednafen.
Need to check the code to determine whether this means that RCR triggers/raised too late, or whether it's a fixed number of opcodes after VBLANK... meaning that VBLANKS is raised too late.