Raising the bar on Phobos unittest coverage

[Joseph Rushton Wakeling]

On 03/18/2013 01:00 AM, Walter Bright wrote:
> With the new -cov=nnn (not pulled yet) and -main, we can now add to the build
> process a minimum bar for unit test coverage.
> 
> The current state looks like this, the percentages are the current coverage
> amounts. It's not bad, but there's a lot of low hanging fruit ready for pull
> requests!
> 
>         $(DMD) -cov=79 -unittest -main -run std\random.d

I've submitted a pull request raising that to 91% :-)

Can I suggest tweaking the make files to print code coverage percentages when
running the Phobos unittests?  Would be useful to check if there are any
unexpected drops or just to have a quick glance where could be useful to try and
help out.