x86inc: Extend FMA_INSTR functionality

Support the cases where the first and last operand of
the XOP instruction are the same.

Also add vpmacsdql emulation.

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
flac/x86: add ff_flac_lpc_32_xop()

Tested on an AMD FX 6300

679081 decicycles in ff_flac_lpc_32_xop, 32768 runs
774425 decicycles in ff_flac_lpc_32_sse4, 32768 runs

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>