native image: hardening csu for old glibc (#827)

Workround of return-to-csu problem for old glibc, use non-initialized
static variables instead of the stack ones. See workround 2 of
https://i.blackhat.com/briefings/asia/2018/asia-18-Marco-return-to-csu-a-new-method-to-bypass-the-64-bit-Linux-ASLR-wp.pdf
3 files changed