[midend-phielimination]消除只有一个incomingvalue的phi指令

src/midend/Pass/Optimize/GVN.cpp

@@ -39,7 +39,7 @@ bool GVN::runOnFunction(Function *func, AnalysisManager &AM) {
     }
     std::cout << "=== GVN completed for function: " << func->getName() << " ===" << std::endl;
   }
-
+  changed |= SysYIROptUtils::eliminateRedundantPhisInFunction(func);
   return changed;
 }