Fix crash on garbage code in tokenlist. The corresponding backtrace along with a testcase is hosted at: https://github.com/orbitcowboy/cppcheck_crash_files/blob/master/crash220.cpp

lib/tokenlist.cpp

@@ -758,6 +758,8 @@ static void compileAnd(Token *&tok, AST_state& state)
     while (tok) {
         if (tok->str() == "&" && !tok->astOperand1()) {
             Token* tok2 = tok->next();
+            if(!tok2)
+               break;
             if (tok2->str() == "&")
                 tok2 = tok2->next();
             if (state.cpp && Token::Match(tok2, ",|)")) {

test/testgarbage.cpp

@@ -50,7 +50,8 @@ private:
         TEST_CASE(garbageCode8); // #5511
         TEST_CASE(garbageCode9); // #5604
         TEST_CASE(garbageCode10);  // #6127
-
+        TEST_CASE(garbageCode11);  
+        
         TEST_CASE(astGarbage);
     }
 
@@ -232,6 +233,10 @@ private:
     void garbageCode10() { // #6127
         checkCode("for( rl=reslist; rl!=NULL; rl=rl->next )");
     }
+    
+    void garbageCode11() { // do not crash
+        checkCode("( ) &");
+    }
 
     void astGarbage() {
         checkCode("--"); // don't crash