Ping^2 Re: Fix lgamma setting signgam for ISO C (bug 15421)

[Joseph Myers]

Ping^2.  I haven't seen any comments on this patch 
<https://sourceware.org/ml/libc-alpha/2015-11/msg00139.html>.  Again, I'm 
seeking review of this patch, since it is adding new symbols and it is 
essentially about ELF alias handling and namespace issues, and only 
incidentally about libm.

-- 
Joseph S. Myers
joseph@codesourcery.com