[1/N] FORTIFY_SOURCE: basic requirements and framework

[op]

Summary

• add required defines and logic to sys/cdefs.h
• add required defines and logic to include/secure/security.h
• hook in to mtree
• factor out the common parts from SSP, and make them common
• added new build knob, and make them by default _disabled_

Test Plan

echo "WITH_FORTIFY=" >> /etc/src.conf
make buildworld

[pfg]

Missing the *_chk functions, without them nothing works.

lib/libc/secure/Symbol.map

11

Empty lists can be dropped (seen in the resolver).

share/mk/bsd.sys.mk

156

This is unnecessary at this time.
I only want the libc support built in by default.

sys/sys/cdefs.h

556

Perhaps a parenthesis for the middles expression would look better even if it isn't strictly necessary.

tools/build/options/WITH_FORTIFY

1

Not necessary at this time.