Don't check if a list is empty with ilist::size.

ilist::size() is O(n) while ilist::empty() is O(1)

llvm-svn: 258636
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index c075da4..8239720 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1502,7 +1502,7 @@
 
     // CodeGen Failure MBB if we have not codegened it yet.
     MachineBasicBlock *FailureMBB = SDB->SPDescriptor.getFailureMBB();
-    if (!FailureMBB->size()) {
+    if (FailureMBB->empty()) {
       FuncInfo->MBB = FailureMBB;
       FuncInfo->InsertPt = FailureMBB->end();
       SDB->visitSPDescriptorFailure(SDB->SPDescriptor);