Update INSTALL to mention latest GCC version successfully used.

[Mike Frysinger]

On 09 Feb 2016 16:56, Carlos O'Donell wrote:
> If nobody objects I'll install this tomorrow to update the fact that newer
> stable GCC can be used to build glibc. I use stable GCC 5.3.1 every day.

there is no 5.3.1 release, but change looks fine otherwise ...
i'm using 5.3.0 myself.
-mike
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://sourceware.org/pipermail/libc-alpha/attachments/20160210/07444ac9/attachment.sig>