x86: use the inline int8x8_fmul_int32 only if inline SSE2 is availbale

Fixes compilation with MSVC. Also does not rely on on earlier config.h
include but include it directly.
h264: give numbers to nalus

Signed-off-by: Janne Grunau <janne-libav@jannau.net>
configure: clang: add -Qunused-arguments to as|ld_flags as well
dca: include dcadsp.h in {arm,x86}/dca.h for checkheaders
mlp: improve request_channel_layout behavior.

Don't decode further substreams if request_channel_layout
is a subset of the current substream's channel_layout.

Before, we would only discard further substreams if
request_channel_layout matched the substream's
channel_layout extactly, thus decoding additional
channels which the caller would probably end up downmixing.
Merge commit '0cffd6fff59f192120dc93aa6c3cb8180f5506e3'

* commit '0cffd6fff59f192120dc93aa6c3cb8180f5506e3':
  x86: use the inline int8x8_fmul_int32 only if inline SSE2 is availbale

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'b141c7b37eb52aca41ac83738f159b63b9c09d5c'

* commit 'b141c7b37eb52aca41ac83738f159b63b9c09d5c':
  h264: give numbers to nalus

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '6398d8fd813490fc3900baf8c788f803d8e17b73'

* commit '6398d8fd813490fc3900baf8c788f803d8e17b73':
  configure: clang: add -Qunused-arguments to as|ld_flags as well

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '5c1c6e82261b856214499b9fef3a08bf3ff6e0ae'

* commit '5c1c6e82261b856214499b9fef3a08bf3ff6e0ae':
  dca: include dcadsp.h in {arm,x86}/dca.h for checkheaders

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'c0c45188e56cfa3050bb39f8299025345b8a204c'

* commit 'c0c45188e56cfa3050bb39f8299025345b8a204c':
  mlp: improve request_channel_layout behavior.

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mlpdec: fix mulichannel output

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mlp_parser: fix multichannel

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