[Reduction] #709: graph_pack_put_8_noclip

Yeah, it's really just a copy of that function with 3 instructions deleted.
[Reverse-engineering] Slot-based PI display

Also covering the two variations for blitting only every second row or
blitting only a 320x200 quarter, as seen in the endings.

So yeah, there's indeed nothing wrong with piread.cpp. TH03 just uses that
separate function that only blits every second row of an image, and indeed
always loads the entire image as it would appear in a PNG conversion. Here's
what happens if you display these images using the non-interlacing function:
https://www.dropbox.com/s/885krj09d9l0890/th03%20PI%20no%20interlace.png