The pattern compare in Blt16BPPBufferPixelateRectWithColor gives neither
operand a size: a memory reference with no register to take the width from,
against an untyped zero. MSVC picks a byte, which is right -- Pattern is
UINT8[8][8], and every other access to it in the block goes through al --
but the source never says so, and clang-cl refuses to guess.
Naming the size changes nothing. cl emits 80 3C 1E 00 before and after.