The problem appears to be the alpha.
This appears to fix the problem:
WRITE(p, "if (floor(v.a * 255.0 + 1.75) %s u_alphacolorref.a) discard;\n", alphaTestFuncs[alphaTestFunc]);
https://github.com/hrydgard/ppsspp/pull/1704
EDIT:
Now I see artifacts that weren't in 0.7.6-460-g6cdf5ea:
This appears to fix the problem:
WRITE(p, "if (floor(v.a * 255.0 + 1.75) %s u_alphacolorref.a) discard;\n", alphaTestFuncs[alphaTestFunc]);
https://github.com/hrydgard/ppsspp/pull/1704
EDIT:
Now I see artifacts that weren't in 0.7.6-460-g6cdf5ea:

