[PATCH, i386]: Implement PR 71246, Missing built-in functions for float128 NaNs

[Joseph Myers]

On Fri, 10 Jun 2016, Uros Bizjak wrote:

> Joseph, does it look OK to you? Richi, I hope I got tree stuff
> implemented correctly.

It's plausible, but really needs testcases (which could examine the 
bit-patterns of __float128 objects initialized using these built-in 
functions, to make sure those are as expected).

-- 
Joseph S. Myers
joseph@codesourcery.com