The graph string is either freed or attached to the filtergraph, so it's best to not leave a dangling pointer with the caller.
SSSE3 is already quite old (introduced 2006 for Intel, 2011 for AMD), so that the overwhelming majority of our users (particularly those that actually update their FFmpeg) will be using the SSSE3 versions.
This is intending to fix the case described in
Recent lld version default to --no-undefined-version, which triggers errors when building multiple libraries.
It syncs with gnulib commit 1790ef25d81983d1d25a77d452c0080345df459b. The main change is to proper support clang by using builtins.
The C2y function uimaxabs has been renamed to umaxabs.
Vulkan has defined all its 3-plane formats as MSB padded.