Require GCC 4.9 or later for building glibc

[Florian Weimer]

On 06/19/2017 05:27 PM, Joseph Myers wrote:
> 2017-06-19  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* configure.ac (libc_cv_compiler_ok): Require GCC 4.9 or later.
> 	* configure: Regenerated.
> 	* manual/install.texi (Tools for Compilation): Document
> 	requirement for GCC 4.9 or later.
> 	* INSTALL: Regenerated.

Okay, as discussed before.

Thanks,
Florian