[kern/kerx] Fix offset base Disable kern Format2. Fix kerx Format2. Manually tested this with Tamil MN font and it works: $ HB_OPTIONS=aat ./hb-shape Tamil\ MN.ttc -u 0B94,0B95 [tgv_au=0+3435|tgc_ka=1@-75,0+1517] HB_OPTIONS=aat ./hb-shape Tamil\ MN.ttc -u 0B94,0B95 --features=-kern [tgv_au=0+3510|tgc_ka=1+1592]