Ubuntu 18 64 bit support

[kedjames]

I noticed in the paper your evaluation was done on Ubuntu 14, Is it possible to evaluate on Ubuntu 18? If so can you assist with the following error:

afl-sensitive/afl-ct/qemu_mode/qemu-2.3.0/user-exec.c: In function ‘cpu_resume_from_signal’:
afl-sensitive/afl-ct/qemu_mode/qemu-2.3.0/user-exec.c:71:37: error: dereferencing pointer to incomplete type ‘struct ucontext’
sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
^~
afl-sensitive/afl-ct/qemu_mode/qemu-2.3.0/user-exec.c: In function ‘cpu_x86_signal_handler’:
afl-sensitive/afl-ct/qemu_mode/qemu-2.3.0/user-exec.c:213:41: error: dereferencing pointer to incomplete type ‘struct ucontext’
#define PC_sig(context) ((context)->uc_mcontext.gregs[REG_RIP])
^
afl-sensitive/afl-ct/qemu_mode/qemu-2.3.0/user-exec.c:232:10: note: in expansion of macro ‘PC_sig’
pc = PC_sig(uc);
^~~~~~
afl-sensitive/afl-ct/qemu_mode/qemu-2.3.0/user-exec.c:237:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
afl-sensitive/afl-ct/qemu_mode/qemu-2.3.0/rules.mak:57: recipe for target 'user-exec.o' failed
make[1]: *** [user-exec.o] Error 1
Makefile:173: recipe for target 'subdir-x86_64-linux-user' failed
make: *** [subdir-x86_64-linux-user] Error 2