Workaround for NetBSD initial-exec and dlopen is not supported?

[David Shao <davshao%gmail.com@localhost>]

Radeon graphics at South Islands and beyond require for 2D
acceleration glamor instead of exa:

http://xorg.freedesktop.org/wiki/RadeonFeature/

These instructions are old, but glamor when building MesaLib (I am
using 10.6.4) requires options:

http://www.freedesktop.org/wiki/Software/Glamor/

--enable-gbm
--enable-shared-glapi
--enable-glx-tls

DragonFly with Radeon kernel drivers roughly equivalent to Linux 3.12
is able to use the full radeonsi / glamor / llvm stack with a Radeon
R7 240.

Considering recent work done on NetBSD's Radeon kernel drivers, NetBSD
with modular-xorg should be able to do the same for the same South
Islands Radeon R7 240 and probably a lot more.   I think the only
obstacle is the error, this time on a Radeon 6450 CAICOS card:

(II) [KMS] Kernel modesetting enabled.
LoaderOpen(/usr/pkg/lib/xorg/modules/libglamoregl.so)
gbm: failed to open any driver (search paths /usr/pkg/lib/dri)
gbm: Last dlopen error: /usr/pkg/lib/libglapi.so.0: Use of initialized
Thread Local Storage with model initial-exec and dlopen is not
supported
failed to load driver: r600
gbm: failed to open any driver (search paths /usr/pkg/lib/dri)
gbm: Last dlopen error: /usr/pkg/lib/libglapi.so.0: Use of initialized
Thread Local Storage with model initial-exec and dlopen is not
supported

This potential problem on NetBSD was already noted in the comments for
the MesaLib port.  Has a workaround been found for this problem yet?