Document how to compile with CFI and how to maintain CFI-safe code
Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com>
Message-Id: <20201204230615.2392-6-dbuono@linux.vnet.ibm.com>
[Make build system section in index.rst and add the new file. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>