RFQ: -R remark options

[Nathan Sidwell]

Hi,
I had a need to add a new type of informative message on the modules 
branch, with an option to enable it.  The message is not a warning or an 
error, but just 'hey, you asked if X happens.  It happens just here'. 
This is emitted as a note.  I chose -fnote-$NAME for the option, but 
that wasn't a very satisfactory solution.

I have learnt that clang has -R$NAME options for exactly this kind of 
informative note.  Presumably with -Rno-$NAME negation.

Presumably we could also use this for optimization notes -- 'I failed to 
vectorize this loop because ...'

thoughts?

nathan

-- 
Nathan Sidwell