prog: don't use reflect.Value.IsZero
prog: don't use reflect.Value.IsZero

reflect.Value.IsZero is added in go1.13, not available in Appengine SDK.
Replace it with DeepEqual+Zero.

xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller