Initial commit from sysy-main

test/10_test.sy

@@ -0,0 +1,14 @@
+//test file for backend lab
+
+int main() {
+  const int a = 1;
+  const int b = 2;
+  int c;
+  
+  if (a == b)
+    c = a + b;
+  else
+    c = a * b;
+  
+  return c;
+}