runtime: heapdump hasn't been updated for a while

[zhaozhiqianghw]

I find the dumpstr in heapdump.go:617 hasn't been updated for a while. It means Go is preparing to remove this feature? Or just forget it? It's still "go1.7 heap dump"

[ianlancetaylor]

We don't use the issue tracker to ask questions. Please see https://golang.org/wiki/Questions . Closing this one.

We only need to update that string when we change the format. There is no intention to change the string with every Go release.