RFC: Update test documentation by deleting "cd test && make"

[Leslie Zhai]

Hi David,

Webrev: http://cr.openjdk.java.net/~lzhai/8221357/webrev.01/

A patch by Jing Tian <jingtian at loongson.cn>
He also fixed two existing grammar issues.

Please review it.

Thanks,
Leslie Zhai