Use BitVector instead of vector<bool> which can be extremely slow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34302 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 83852ca..57a73d2 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -461,7 +461,7 @@
       // If the kill happens after the definition, we have an intra-block
       // live range.
       if (killIdx > defIndex) {
-        assert(vi.AliveBlocks.empty() &&
+        assert(vi.AliveBlocks.none() &&
                "Shouldn't be alive across any blocks!");
         LiveRange LR(defIndex, killIdx, ValNum);
         interval.addRange(LR);