Double free in i2o_ECPublicKey

PR: 3338
crypto/armcap.c: detect ARMv8 capabilities [in 32-bit build].
sha/asm/sha1-armv4-large.pl: add NEON and ARMv8 code paths.
sha/asm/sha256-armv4.pl: add ARMv8 code path.
C64x+ assembly pack: make it work with older toolchain.
C64x+ assembply pack: add RC4 module.
md5/asm/md5-[586|x86_64].pl: +15% on Atom.

[MD5 is hardly relevant, just cleaning up repository]
Merge remote branch 'upstream/master'