community/zstd: fix ~15% speed degradation on x86*

This is the same memcpy()-in-hot-path xxHash problem as described
in community/xxhash commit message.

The bug makes "zstd -1" or "zstd -t" ~15% slower on x86_64 though
higher levels (>= 9) are almost unaffected.

Other aport changes:
 - make sure zlib/lzma/lz4 support is not compiled in automatically
   (status quo, just make it explicit);
 - re-enable armv7 since it is certainly well-supported by upstream,
   was disabled by some script in the first place and should not be
   affected by "Bus error" (i.e. some alignment problem) mentioned in
   commit 2bae66907...
 - use faster and shorter "make check" (unlike extensive "make test")
   on arm* builders.

0 files changed, 0 insertions, 0 deletions