[patch] Enable lightweight checks with _GLIBCXX_ASSERTIONS.

[Jonathan Wakely]

On 08/09/15 21:52 +0200, François Dumont wrote:
>Very good approach, I will start moving light checks from _GLIBCXX_DEBUG
>implementation to normal one then.

Great, thanks. I *think* my patch got most of the lightweight checks
already.

We could maybe include the irreflexivity checks, although it does
change the number of calls to the comparison function, which is not
allowed for some algorithms.

I'll commit my patch today.