Require aligned memory for everything that needs it

Altivec, NEON, and SSE require more alignment than standard malloc()
guarantees, whereas MMX does not.  Update checks to reflect this.

Originally committed as revision 19438 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1040,6 +1040,8 @@ sse_deps="mmx"
 ssse3_deps="sse"
 vis_deps="sparc"
 
+need_memalign="altivec neon sse"
+
 # decoders / encoders / hardware accelerators
 aac_decoder_select="fft mdct"
 ac3_decoder_select="fft mdct"
@@ -1668,21 +1670,21 @@ case $target_os in
         oss_outdev_extralibs="-lossaudio"
         ;;
     openbsd)
-        disable need_memalign
+        enable malloc_aligned
         LIBOBJFLAGS='$(PIC)'
         SHFLAGS='-shared'
         oss_indev_extralibs="-lossaudio"
         oss_outdev_extralibs="-lossaudio"
         ;;
     freebsd|dragonfly)
-        disable need_memalign
+        enable malloc_aligned
         ;;
     bsd/os)
         osextralibs="-lpoll -lgnugetopt"
         strip="strip -d"
         ;;
     darwin)
-        disable need_memalign
+        enable malloc_aligned
         SHFLAGS='-dynamiclib -Wl,-single_module -Wl,-install_name,$(SHLIBDIR)/$(SLIBNAME),-current_version,$(LIBVERSION),-compatibility_version,$(LIBMAJOR) -Wl,-read_only_relocs,suppress'
         strip="strip -x"
         FFLDFLAGS="-Wl,-dynamic,-search_paths_first"
@@ -1697,7 +1699,7 @@ case $target_os in
         target_os=mingw32
         LIBTARGET=i386
         if enabled x86_64; then
-            disable need_memalign
+            enable malloc_aligned
             LIBTARGET=x64
         elif enabled arm; then
             LIBTARGET=arm
@@ -1840,8 +1842,6 @@ enabled version3 && { enabled gpl && enable gplv3 || enable lgplv3; }
 
 check_deps $ARCH_EXT_LIST
 
-test -z "$need_memalign" && need_memalign="$mmx"
-
 #Darwin CC versions
 if test $target_os = darwin; then
     if enabled xlc; then
@@ -2091,7 +2091,8 @@ check_header vdpau/vdpau.h
 check_header vdpau/vdpau_x11.h
 check_header X11/extensions/XvMClib.h
 
-if enabled sse && { ! enabled_any memalign memalign_hack posix_memalign && enabled need_memalign ;} ; then
+if ! enabled_any memalign memalign_hack posix_memalign malloc_aligned &&
+     enabled_any $need_memalign ; then
     die "Error, no aligned memory allocator but SSE enabled, disable it or use --enable-memalign-hack."
 fi