OpenMPOpt: Avoid using getNumUses (llvm#136349)

Author: arsenm

llvm/lib/Transforms/IPO/OpenMPOpt.cpp

@@ -1535,7 +1535,7 @@ struct OpenMPOpt {
     // safely remove it.
     // TODO: This should be somewhere more common in the future.
     if (GlobalVariable *GV = M.getNamedGlobal("__llvm_rpc_client")) {
-      if (GV->getNumUses() >= 1)
+      if (GV->hasNUsesOrMore(1))
         return false;
 
       GV->replaceAllUsesWith(PoisonValue::get(GV->getType()));