Disable thread-related tests on OSX due to the bug on gcc-4.8.1

src/tests/kernel/arith.cpp

@@ -83,10 +83,13 @@ static void tst6() {
     std::cout << "tst6\n";
     std::cout << mk_int_add_fn().raw() << "\n";
     std::cout << mk_int_add_fn().raw() << "\n";
+
+    #ifndef __APPLE__
     std::thread t1([](){ std::cout << "t1: " << mk_int_add_fn().raw() << "\n"; });
     t1.join();
     std::thread t2([](){ std::cout << "t2: " << mk_int_add_fn().raw() << "\n"; });
     t2.join();
+    #endif
     std::cout << mk_int_add_fn().raw() << "\n";
 }
 

src/tests/kernel/threads.cpp

@@ -48,6 +48,7 @@ static void tst1() {
     a = f(a, a);
     std::vector<std::thread> ts;
 
+    #ifndef __APPLE__
     for (unsigned i = 0; i < 8; i++) {
         ts.push_back(std::thread([&](){ mk(a); }));
     }
@@ -55,6 +56,7 @@ static void tst1() {
         ts[i].join();
         std::cout << "finished " << i << "\n";
     }
+    #endif
 }
 
 int main() {