[RFC][PATCH] New configure option "--disable-ifunc"

[Maria Guseva]

> On Wed, 13 May 2015, Maria Guseva wrote:

>> The proposed patch adds a new configure option in order to disable 
>> IFUNC usage in Glibc.

> What problem is this solving?  Each configure option adds to the
combinatorial explosion of poorly-tested different ways to configure >
glibc, so there needs to be strong justification for adding a new option
(and increasing the minimum supported version of build tools > can often be
preferred to having conditionals to support older tools, depending on how
widespread the older tools are).

We faced issues when Glibc was used with Prelink. As I know the latest
Prelink supports ifuncs but older versions are not working correctly with
it. We need to disable ifuncs in Glibc for such case.