fate: force the simple idct for xvid custom matrix test
The original test without a forced idct is still useful since it tests the switching of the idct algorithm/permutation on x86 with MMX. MMXext or SSE2. Make sure the test runs only if MMX inline asm is available and force -cpuflags to all. Add the required bitexact flag for both tests.
Showing with 45 additions and 21 deletions