These changes make rdo build on my rpi, probably because this specific
GCC version requires arguments in the order we now supply.
We also disable ASAN in the debug build (for now), as it seems to cause
a segfault on my rpi.
We now have a normal and a debug build, both of which
have full RELRO, appropriate handling of warnings and
the default build has D_FORTIFY_SOURCE set to 2.