[libstdc++] decimal float support (take 2)

[Paolo Carlini]

Hi,

> Tests are coming in a separate patch.  I'd like to get this in for  
> 4.5.
> What changes are needed (with full testing) before it can go in as an
> experimental feature?

First, thanks for this work. Since you are asking, I quickly went  
through the code and the formatting seems rather off wrt the normal  
conventions in the library, for example: no space between a function  
name and the open round brace; no space between type and &; new line  
before open curly brace, eg, for the body of a class definition,  
likewise for a namespace; please have a look to the existing code for  
guidance, we are rather consistent.

Thanks again,
Paolo

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