getset.h, getset.cpp: Deduplicate the S9xGet* and S9xSet* functions in the output executable.

Having multiple distinct implementations containing the same code places a greater burden on the host's instruction cache.
tile.cpp: Counter-intuitive optimisation inspired by Snes9x 1.43.

In Snes9x 1.43, instead of using GFX.S[Offset + N] and so on to render a tile, a local pointer variable was incremented by GFX.PPL each line.
Revert "tile.cpp: Optimise tile flipping."

This reverts commit 0d7cd680c2dd0b70df893b573b4446629c884c94.

Conflicts:
	pocketsnes/snes9x/tile.cpp