Mini proposal: rename float.min to float.min_normal

[Don]

Don wrote:
> This is another small imperfection we should get rid of.
> The floating point types have a property called ".min", but unlike the 
> integer ".min", it's not the minimum!

> This misnaming is bad because (a) it causes confusion; and (b) it 
> interfere with generic code, requiring special cases.
> We should rename this while we have the chance. I don't think we should 
> depart too far from the C/C++ name, but anything other than ".min" will 
> work. I propose:
> 
> real.min ----> real.min_normal
> If there is no objection to this, I will create a patch. It's very simple.

Patch is in bugzilla 3446. It took about 2 minutes to do.