Kir Kolyshkin 8befd2d809 TestImportExtremelyLargeImageWorks: optimize DevZero ...

According to https://github.com/golang/go/issues/5373, go recognizes
(and optimizes for) the following syntax:

```go
for i := range b {
	b[i] = 0
}
```

so let's use it. Limited testing shows ~7.5x speed increase,
compared to the previously used syntax.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Upstream-commit: f0cab0e28512de5eecc0412212425cc74d62af71
Component: engine

2017-12-28 13:08:41 -08:00

..

test/environment

[integration] ensure frozen images are loaded

2017-10-20 16:51:13 -04:00

testutil

TestImportExtremelyLargeImageWorks: optimize DevZero

2017-12-28 13:08:41 -08:00