For the four Boost.Thread tests that are intended to fail on C++98/03

compilers, add expected failure markup for Clang.


[SVN r61628]

status/explicit-failures-markup.xml

@@ -4926,6 +4926,7 @@ With aC++, the tests compile cleanly in strict ansi mode and succeed.
             <toolset name="darwin-*"/>
             <toolset name="sun-*"/>
             <toolset name="acc-*"/>
+            <toolset name="clang-darwin-*"/>
             <note author="Anthony Williams" date="2009-10-28">
 These tests will fail in most compilers that don't support rvalue references.
             </note>
@@ -4933,6 +4934,7 @@ These tests will fail in most compilers that don't support rvalue references.
         <mark-expected-failures>
             <test name="test_thread_return_local"/>
             <test name="test_thread_return_local_lib"/>
+            <toolset name="clang-darwin-*"/>
             <toolset name="gcc-3.4.3"/>
             <toolset name="gcc-4.2.4"/>
             <toolset name="gcc-4.3.3"/>
@@ -4943,6 +4945,7 @@ These tests will fail in most compilers that don't support rvalue references.
             <toolset name="acc-*"/>
             <toolset name="msvc-*"/>
             <toolset name="intel-*"/>
+            <toolset name="clang-darwin-*"/>
             <note author="Anthony Williams" date="2009-10-28">
 These tests will fail in most compilers that don't support rvalue references.
             </note>