[midend-reg2mem]增加reg2mem遍，应用未定义值，增加inst迭代器查找方法，通过编译且脚本运行通过率不变

src/Pass.cpp

@@ -4,6 +4,7 @@
 #include "SysYIRPrinter.h"
 #include "DCE.h"
 #include "Mem2Reg.h"
+#include "Reg2Mem.h"
 #include "Pass.h"
 #include <iostream>
 #include <queue>
@@ -67,6 +68,10 @@ void PassManager::runOptimizationPipeline(Module* moduleIR, IRBuilder* builderIR
       this->addPass(&Mem2Reg::ID);
       this->run();
 
+      this->clearPasses();
+      this->addPass(&Reg2Mem::ID);
+      this->run();
+
       if (DEBUG) std::cout << "--- Custom optimization sequence finished ---\n";
     }