It's not a dedicated CPU instruction, but rather a write to an MMIO register with a certain bit set. And many games will follow patterns like computing the register value during game logic, saving it in RAM, and copying the value from RAM to the register later during vertical blanking, or they might have code path to enable hires mode that is present but not used if the code came from a library or engine. So in general, the problem is undecidable; and limited to SNES games, probably not very realistic.

The most reliable thing to do is probably to play through the entire game in an emulator (maybe from a TAS movie) and record whether it actually enables high-res mode or not.