libc-glibc: remove 2.3.6

This is an obsolete version which is no longer used by any sample (the only
user, the ia64 sample, has been removed).

It also makes the code path a bit complex, with twists just to accomodate
that version. Removing the version will make those twists go away, and
will ease commonalisation of glibc and eglibc in the future (hopefully!).

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

 # Default test suite configuration

 # Default DejaGnu configuration

 DG_TOOLNAME = gcc

 DG_TARGET_HOSTNAME = 127.0.0.1

 DG_TARGET_USERNAME = root

 # Default tests

 DG_C_TESTS = 

 DG_CPP_TESTS =