Revert "Work around a Clang trunk (towards 3.6) -Werror,-Wunused-value"

This reverts commit 146bd125,
Clang's r224465 does not look really useful the way it is, so work around
that directly in Clang for now.

tools/source/debug/debug.cxx

@@ -324,20 +324,7 @@ TOOLS_DLLPUBLIC void DbgUnhandledException(const css::uno::Any & caught, const c
         }
         if ( exception.Context.is() )
         {
-#if defined __clang__
-#if __has_warning("-Wunused-value")
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-value"
-    // "expression with side effects will be evaluated despite being used as an
-    // operand to 'typeid'"
-#endif
-#endif
             const char* pContext = typeid( *exception.Context.get() ).name();
-#if defined __clang__
-#if __has_warning("-Wunused-value")
-#pragma GCC diagnostic pop
-#endif
-#endif
             sMessage += "\ncontext: ";
             sMessage += pContext;
         }