In cases where a test result is not found, for example when a panic
happened, a dummy failing test is added to the report. Since we don't
know exactly what failed, its error message was simply "Run error". This
has been renamed to "Runtime error".
Go doesn't omit empty parent tags for empty values[1], so we'll work
around this for now by creating a pointer to the property slice.
[1]: https://github.com/golang/go/issues/7233.
The Result Data field contains the test output that was read from stdin.
This used to be a chardata field, which escapes many characters in the
resulting XML. Writing this output with <![CDATA[]]> tags makes the raw
XML output much easier to read in e.g. a text editor.