Fix some error because of emitPush

src/main/java/chocopy/pa3/CodeGenImpl.java

@@ -316,6 +316,7 @@ public class CodeGenImpl extends CodeGenBase {
 
         @Override
         public Void analyze(AssignStmt node) {
+            backend.emitADDI(SP, SP, -4, "Increment stack ptr by 1 for Condition");
             node.value.dispatch(this);
             RiscVBackend.Register tmpReg = /*regMgr.borrowOneTmp()*/ T6;
             RiscVBackend.Register tmpReg2 = /*regMgr.borrowOneTmp()*/ T5;
@@ -371,6 +372,7 @@ public class CodeGenImpl extends CodeGenBase {
 
         @Override
         public Void analyze(IfStmt node) {
+            backend.emitADDI(SP, SP, -4, "Increment stack ptr by 1 for Condition");
             node.condition.dispatch(this);
             RiscVBackend.Register tmpReg = /*regMgr.borrowTmp()*/ T6;
             betterBackend.emitPop(tmpReg, "IfStmt: Get condition");