FYI: Fix for gcc PR36312 breaks glibc builds over usage of /dev/null as input and output file.

[Markus Trippelsdorf]

On 2014.11.19 at 09:44 -0500, Carlos O'Donell wrote:
> The fix for gcc PR36312 breaks glibc builds.
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36312
> 
> The fix disallows this common configure idiom:
> 
> configure:72: checking for AVX support
> configure:78: /home/triegel/local/gcc/bin/gcc -mavx -xc /dev/null -S -o /dev/null
> gcc: fatal error: input file '/dev/null' is the same as output file
> compilation terminated.
> configure:81: $? = 1
> configure:89: result: no
> 
> PR is reopened with a request to fix.
> 
> Alternatively we could discuss changing glibc, but I think
> this will impact more than just glibc.

No need to change anything. The bug is already fixed:
https://gcc.gnu.org/viewcvs?rev=217789&root=gcc&view=rev

-- 
Markus