Simplified access code

[radarhere]

1. The put_pixel function is only currently used for LA, La and PA.
   

   Pillow/src/libImaging/Access.c

   Lines 187 to 208 in b945154

   	ADD("1", get_pixel_8, put_pixel_8);
   	ADD("L", get_pixel_8, put_pixel_8);
   	ADD("LA", get_pixel, put_pixel);
   	ADD("La", get_pixel, put_pixel);
   	ADD("I", get_pixel_32, put_pixel_32);
   	ADD("I;16", get_pixel_16L, put_pixel_16L);
   	ADD("I;16L", get_pixel_16L, put_pixel_16L);
   	ADD("I;16B", get_pixel_16B, put_pixel_16B);
   	ADD("I;16N", get_pixel_16, put_pixel_16L);
   	ADD("I;32L", get_pixel_32L, put_pixel_32L);
   	ADD("I;32B", get_pixel_32B, put_pixel_32B);
   	ADD("F", get_pixel_32, put_pixel_32);
   	ADD("P", get_pixel_8, put_pixel_8);
   	ADD("PA", get_pixel, put_pixel);
   	ADD("RGB", get_pixel_32, put_pixel_32);
   	ADD("RGBA", get_pixel_32, put_pixel_32);
   	ADD("RGBa", get_pixel_32, put_pixel_32);
   	ADD("RGBX", get_pixel_32, put_pixel_32);
   	ADD("CMYK", get_pixel_32, put_pixel_32);
   	ADD("YCbCr", get_pixel_32, put_pixel_32);
   	ADD("LAB", get_pixel_32, put_pixel_32);
   	ADD("HSV", get_pixel_32, put_pixel_32);

Pillow/src/libImaging/Access.c

Lines 130 to 137 in b945154

	static void
	put_pixel(Imaging im, int x, int y, const void *color) {
	if (im->image8) {
	im->image8[y][x] = *((UINT8 *)color);
	} else {
	memcpy(&im->image32[y][x], color, sizeof(INT32));
	}
	}

Since these are not image8 modes, it would be simpler to just call put_pixel_32 instead

Pillow/src/libImaging/Access.c

Lines 172 to 175 in b945154

	static void
	put_pixel_32(Imaging im, int x, int y, const void *color) {
	memcpy(&im->image32[y][x], color, sizeof(INT32));
	}

and remove put_pixel.

2. get_pixel is similarly only currently used for LA, La and PA.

It does have unique behaviour, so we can't remove it completely.

Pillow/src/libImaging/Access.c

Lines 48 to 65 in b945154

	static void
	get_pixel(Imaging im, int x, int y, void *color) {
	char *out = color;
	/* generic pixel access*/
	if (im->image8) {
	out[0] = im->image8[y][x];
	} else {
	UINT8 *p = (UINT8 *)&im->image32[y][x];
	if (im->type == IMAGING_TYPE_UINT8 && im->bands == 2) {
	out[0] = p[0];
	out[1] = p[3];
	return;
	}
	memcpy(out, p, im->pixelsize);
	}
	}

However, this PR removes the check for image8, since it is false for these modes, and the check if this is UINT8 2 bands, since it is true for these modes, and renames the function to get_pixel_32_2bands to indicate that it is specific.