Subzero: Fix a build error against LLVM trunk.

src/IceTargetLoweringARM32.cpp

Index: src/IceTargetLoweringARM32.cpp
diff --git a/src/IceTargetLoweringARM32.cpp b/src/IceTargetLoweringARM32.cpp
index 0add99a71097ed16f218962418489fe75f688530..7564652df1c44c0c8c448a0bc595a4a857697077 100644
--- a/src/IceTargetLoweringARM32.cpp
+++ b/src/IceTargetLoweringARM32.cpp
@@ -1703,7 +1703,7 @@ void TargetARM32::addEpilog(CfgNode *Node) {
 
   // Convert the reverse_iterator position into its corresponding (forward)
   // iterator position.
-  InstList::iterator InsertPoint = RI.base();
+  InstList::iterator InsertPoint = reverseToForwardIterator(RI);
   --InsertPoint;
   Context.init(Node);
   Context.setInsertPoint(InsertPoint);