Comment 6 for bug 1657596

Just some follow-up notes:

Add -fPIC and -fPIE to debian_cflags, debian_ldflags; make sure hardening-flags=+all,-fPIE for the DEBIAN_LDFLAGS string where it modifies the flags to run with for certain cases. This is nearly identical to what we had to do for Trusty in Ubuntu an eternity ago, but with a few changes.