构建IR打印器，llvm风格，跑通大部分样例(9/10)，待修复

src/sysyc.cpp

@@ -8,7 +8,8 @@ using namespace std;
 using namespace antlr4;
 // #include "Backend.h"
 #include "SysYIRGenerator.h"
-#include "RISCv32Backend.h"
+#include "SysYIRPrinter.h"
+// #include "LLVMIRGenerator.h"
 using namespace sysy;
 
 static string argStopAfter;
@@ -71,22 +72,14 @@ int main(int argc, char **argv) {
 
 
   // visit AST to generate IR
-  SysYIRGenerator generator;
-  generator.visitCompUnit(moduleAST);
-  if (argStopAfter == "ir") {
-      // auto module = generator.get();
-      // module->print(cout);
-      return EXIT_SUCCESS;
-  }
 
-  // generate assembly
-  auto module = generator.get();
-  sysy::RISCv32CodeGen codegen(module);
-  string asmCode = codegen.code_gen();
-  if (argStopAfter == "asm") {
-    cout << asmCode << endl;
+  if (argStopAfter == "ir") {
+    SysYIRGenerator generator;
+    generator.visitCompUnit(moduleAST);
+    auto moduleIR = generator.get(); 
+    SysYPrinter printer(moduleIR);
+    printer.printIR();
     return EXIT_SUCCESS;
   }
-
   return EXIT_SUCCESS;
 }