[Bug target/58066] GCC mis-compiles access to TLS variable with -fPIC on x86_64

[ppluzhnikov at google dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066

--- Comment #2 from Paul Pluzhnikov <ppluzhnikov at google dot com> ---
(In reply to Andrew Pinski from comment #1)

> Which most Linux distro default to anyways ...

Ubuntu 12.04.1 LTS doesn't.
Configuring trunk GCC on it doesn't default to GNU2 TLS either.

What is the way to turn it on?