Since linux binaries are (mostly) always compiled with gcc, look for
the gcc signature in the .comment section header: "\0 GCC: (GNU) ".
I've changed the probe order in kern/exec_elf.c to probe for linux ELF
binaries first and fall back to SVR4 binaries. This makes statically
linked binaries work for both linux and svr4. Note that gcc-compiled
svr4 binaries, still contain the operating system signature first and
then the GCC signature, so there is no conflict. Yes this is a hack.
mycroft