Optimize pure C unscaled yuv2rgb.

Aligning the tables reduces the amount of code generated on
e.g. ARM as the offset constant then has few enough set bits
so it can be encoded inside a single instruction instead of 2.
Ideally all should be declared aligned, but the DECLARE_ALIGNED
macros does not work with pointer tables, thus also reordered
the tables.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
avcodec/jpeglsdec: check err value for ls_get_code_runterm()

Fixes infinite loop
Fixes Ticket3086

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>