tree checksum vpatch file

all signers: asciilifeform bvt diana_coman

antecedents: ffa_ch2_logicals.kv

press order:

ffa_ch1_genesis.kvasciilifeform bvt diana_coman
ffa_ch2_logicals.kvasciilifeform bvt diana_coman
ffa_ch3_shifts.kvasciilifeform bvt diana_coman

hunks:
ffa/ffademo/demo_ch2.adb
ffa/ffademo/demo_ch3.adb
ffa/ffademo/demo_ch3.ads
ffa/ffademo/ffa_demo.adb
ffa/libffa/fz_basic.adb
ffa/libffa/fz_basic.ads
ffa/libffa/fz_bitop.adb
ffa/libffa/fz_bitop.ads
ffa/libffa/fz_cmp.adb
ffa/libffa/fz_cmp.ads
ffa/libffa/fz_pred.adb
ffa/libffa/fz_pred.ads
ffa/libffa/fz_shift.adb
ffa/libffa/fz_shift.ads