[PATCH v2] elf: Release dl_load_lock before running dlopen constructors (BZ 15686)

[Artem Proskurnev]

> My concern regarding the removal of a lock that applications could
> previously rely on remains.
>
> Thanks,
> Florian
>
In the v3 version of the patch, I added the ability to restore the 
default behavior for applications that may be affected by this change:

GLIBC_TUNABLES=glibc.rtld.strict_init_order=1 ./your_app

Artem