Disable drd/tests/std_thread.cpp for clang.
clang 3.3 produces an error message for /usr/include/c++/4.6/chrono
which happens to get included somewhere inside <thread>.
This happens with C++ headers from:
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3. 


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13620 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/drd/tests/Makefile.am b/drd/tests/Makefile.am
index 2067c0d..dabbe52 100644
--- a/drd/tests/Makefile.am
+++ b/drd/tests/Makefile.am
@@ -365,10 +365,14 @@
   tsan_unittest
 endif
 
+# clang 3.3 will generate errors about libstdc++ headers from 
+# gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
+if ! COMPILER_IS_CLANG
 if HAVE_SHARED_POINTER_ANNOTATION
 check_PROGRAMS += \
   std_thread
 endif
+endif
 
 if HAVE_OPENMP
 check_PROGRAMS += omp_matinv omp_prime omp_printf