IsZero undefined

使用golang版本1.12.17，提示找不到reflect.IsZero
github.com/bilibili/gengine/internal/core/is_nil.go:32:22: value.Field(i).IsZero undefined (type reflect.Value has no field or method IsZero)

翻了下version note发现这个IsZero是1.13才引入的？为什么gengine文档上写支持1.12.x呢?

Start with internal/core/is_nil.go at line 32 and compare the reflect.Value API available in Go 1.12.17 with the version used by this code. Verify the compatibility behavior by building or testing with Go 1.12.17; done means the package no longer reports an undefined IsZero method while preserving its nil-checking behavior.

Written by the indexing model from the issue text.