HACL native library compile on ubuntu fails on "undefined reference to '__explicit_bzero_chk'"

[JohnLCaron]

Lib_Memzero0.c:function Lib_Memzero0_memzero: error: undefined reference to '__explicit_bzero_chk'

It appears that Kotlin/Native must use glibc 2.19, which doesnt include explicit_bzero, see https://youtrack.jetbrains.com/issue/KT-43501.

in Lib_Memzero.c:

#elif (defined(linux) && !defined(LINUX_NO_EXPLICIT_BZERO)) || defined(FreeBSD)
explicit_bzero(dst, len_);

So we just can define LINUX_NO_EXPLICIT_BZERO, maybe in libhacl.def:

compilerOpts.linux = -Ilibhacl/include -DLINUX_NO_EXPLICIT_BZERO

but that didnt work.

For now I modified Lib_Memzero.c directly and it works now.

1. define LINUX_NO_EXPLICIT_BZERO so we dont have to modify source.
2. watch for Kotlin/Native upgrade to glib 2.25+

[JohnLCaron]

Hopefully this will be superceded by #200