[backend]将testdata/下的测例替换为了赛方测试用例，更新了测试脚本

testdata/functional/37_op_priority3.sy

@@ -0,0 +1,7 @@
+//test the priority of  unary operator and binary operator
+int main(){
+    int a, b;
+    a = 10;
+    b = 30;
+    return a - -5 + b + -5;
+}