sys/targets: use a different SYZ_DATA_OFFSET for 32-bit FreeBSD (#1809)
sys/targets: use a different SYZ_DATA_OFFSET for 32-bit FreeBSD (#1809)

* sys/targets: use a different SYZ_DATA_OFFSET for 32-bit FreeBSD

It seems that the value used on all platforms (512 << 20) does
not work on 32-bit FreeBSD when using the clang tools.
Try (256 << 20) instead.

* sys/targets: add comment why a non-default value is needed
google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller