drd changes (Bart Van Assche)

- The exp-drd regression tests now run without producing assertion
failures and without hanging on Red Hat 7.3. It doesn't make sense
however to run exp-drd on Red Hat 7.3 -- while exp-drd works fine with
the NPTL, more work would be required to make exp-drd work with
linuxthreads.
- Converted several tl_assert() calls into error messages.
- Added a regression test called pth_barrier, which tests whether data
races are detected in a program that uses barriers. The output exp-drd
produces for this test program is not yet correct however.
- Updated exp-drd/TODO.txt.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7358 a5019735-40e9-0310-863c-91ae7b9d1cf9
11 files changed