Add thread_local test

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/shell/lean.cpp

@@ -1,7 +1,9 @@
 #include <iostream>
+#include <thread>
 #include "version.h"
 #include "name.h"
 #include "mpq.h"
+#include "mpbq.h"
 
 void tst1() {
     lean::name n1("foo");
@@ -15,9 +17,52 @@ void tst2() {
     std::cout << n1*n2 << "\n";
 }
 
+void tst3() {
+    std::cout << "Binary rationals...\n";
+    lean::mpbq n1(12, 3);
+    std::cout << n1 << "\n";
+    lean::mpbq n2(2);
+    lean_assert(n1 < n2);
+
+    std::thread t1([](){
+            for (unsigned i = 0; i < 10000000; i++) {
+                lean::mpbq n1(13, 3);
+                lean::mpbq n2(2);
+                lean_assert(n1 < n2);
+            }});
+    
+    std::thread t2([](){
+            for (unsigned i = 0; i < 10000000; i++) {
+                lean::mpbq n1(500000001,3);
+                lean::mpbq n2(20000000);
+                lean_assert(n2 < n1);
+            }});
+
+    std::thread t3([](){
+            for (unsigned i = 0; i < 10000000; i++) {
+                lean::mpbq n1(1200001, 6);
+                lean::mpbq n2(22221, 7);
+                lean_assert(n1 > n2);
+            }});
+
+    t1.join();
+    t2.join();
+    t3.join();
+}
+
+void tst4() {
+    for (unsigned i = 0; i < 10000000; i++) {
+        lean::mpbq n1(1200001, 6);
+        lean::mpbq n2(22221, 7);
+        lean_assert(n1 > n2);
+    }
+}
+
 int main() {
     std::cout << "Lean (version " << LEAN_VERSION_MAJOR << "." << LEAN_VERSION_MINOR << ")\n";
     tst1();
     tst2();
+    tst3();
+    std::cout << "done\n";
     return 0;
 }