Add 'remark' diagnostic type in clang

[Chris Lattner]

On Feb 25, 2014, at 2:41 AM, Tobias Grosser <tobias at grosser.es> wrote:

> On 02/25/2014 11:32 AM, David Majnemer wrote:
>> You've added some extra whitespace in the definition
>> of CXDiagnosticSeverity.
>> Perhaps more importantly, the enum isn't in increasing order anymore.
> 
> Hi David,
> 
> thanks for the fast review.
> 
> I fixed the whitespace issue.
> 
> The order was intentional. I wanted to list the fields sorted by severity, because this is how they are sorted logically. However, we need to use '= 5' for the new diagnostic to not break the ABI here (these are the c bindings). Would you propose another way to write this enum?

Is "remark" better than "informative" diagnostics?  Is there prior art in other compilers that would be worth following?

-Chris