Implement C _FloatN, _FloatNx types [version 6]

[Joseph Myers]

On Fri, 19 Aug 2016, Richard Biener wrote:

> >> Can you quickly verify if LTO works with the new types?  I don't see anything
> >> that would prevent it but having new global trees and backends initializing them
> >> might come up with surprises (see tree-streamer.c:preload_common_nodes)
> >
> > Well, the execution tests are in gcc.dg/torture, which is run with various
> > options including -flto (and I've checked the testsuite logs to confirm
> > these tests are indeed run with such options).  Is there something else
> > you think should be tested?
> 
> No, I think that's enough.

Then I'll commit the patch later today in the absence of comments from 
other libcpp maintainers (and then go on to update and retest the built-in 
functions patch).

-- 
Joseph S. Myers
joseph@codesourcery.com