title: Error while build ffmpeg for iOS
body: <p>I'm trying to build fmmpeg for iOS with the following config:</p>
  
  <p><code>
  ./configure --prefix=build/armv7 --disable-ffmpeg --disable-ffplay --disable-ffprobe --disable-ffserver --enable-avutil --enable-avresample --enable-cross-compile --sysroot="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk" --target-os=darwin --cc=gcc  --extra-cflags="-arch armv7 -mfpu=neon -miphoneos-version-min=6.0" --extra-ldflags="-arch armv7 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk -miphoneos-version-min=6.0" --arch=arm --cpu=cortex-a9 --enable-pic
  </code></p>
  
  <p>when i try to make it i'm receiving the follow error:</p>
  
  <p><code>
  AS  libavcodec/arm/vc1dsp_neon.o
  libavcodec/arm/vc1dsp_neon.S:751:10: error: unexpected token in argument list
    ra .dn d28.i8
           ^
  libavcodec/arm/vc1dsp_neon.S:752:10: error: unexpected token in argument list
    rb .dn d29.i8
           ^
  libavcodec/arm/vc1dsp_neon.S:753:10: error: unexpected token in argument list
    rc .dn d30.i8
           ^
  libavcodec/arm/vc1dsp_neon.S:754:10: error: unexpected token in argument list
    rd .dn d31.i8
           ^
  libavcodec/arm/vc1dsp_neon.S:757:14: error: invalid operand for instruction
          vmov ra, #4 
               ^
  libavcodec/arm/vc1dsp_neon.S:758:14: error: invalid operand for instruction
          vmov rb, #53 
               ^
  libavcodec/arm/vc1dsp_neon.S:759:14: error: invalid operand for instruction
          vmov rc, #18 
               ^
  libavcodec/arm/vc1dsp_neon.S:760:14: error: invalid operand for instruction
          vmov rd, #3 
               ^
  libavcodec/arm/vc1dsp_neon.S:864:10: error: unexpected token in argument list
    ra .dn d28.i16
           ^
  libavcodec/arm/vc1dsp_neon.S:865:10: error: unexpected token in argument list
    rb .dn d29.i16
           ^
  </code></p>
  
  <p>what could be the error?</p>