libc/uClibc: workaround for a MIPS TLS issue

Some macros declarations were missing, so we duplicate them.
See the added patch description for more information.

----> THIS IS A DIRTY HACK! <----

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 reporter_name="Ioannis E. VENETIS"

 reporter_url="http://sourceware.org/ml/crossgcc/2009-11/msg00109.html"

 reporter_comment=""