[midend-IVE]参考libdivide库，实现了魔数的正确求解，如果后续出错直接用API或者不要除法强度削弱了

src/include/midend/IR.h

@@ -864,6 +864,8 @@ public:
         return "shl";
       case kSra:
         return "ashr";
+      case kMulh:
+        return "mulh";
       default:
         return "Unknown";
     }

src/include/midend/Pass/Optimize/LoopStrengthReduction.h

@@ -132,7 +132,7 @@ private:
    * @param divisor 除数
    * @return {魔数, 移位量}
    */
-  std::pair<int64_t, int> computeMulhMagicNumbers(int divisor) const;
+  std::pair<int, int> computeMulhMagicNumbers(int divisor) const;
   
   /**
    * 生成除法替换代码