enhance security using special compilation options

gcc/ld have different options that can make resulting binaries more secure against buffer/stack overflow exploits. RedHat uses most of them for distribution binaries. We need to analyze these options, understand the benefits and drawbacks, and possibly use them too in our builds.
The (incomplete) list is

-pie

-Wp,-D_FORTIFY_SOURCE=2

-fstack-protector --param=ssp-buffer-size=4

-Wl,-z,relro,-z,now