Silencing a -Wsign-compare warning; NFC.

llvm-svn: 237794
diff --git a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
index 5050705..06ade39 100644
--- a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
+++ b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
@@ -1877,7 +1877,7 @@
 static void rematerializeLiveValues(CallSite CS,
                                     PartiallyConstructedSafepointRecord &Info,
                                     TargetTransformInfo &TTI) {
-  const int ChainLengthThreshold = 10;
+  const unsigned int ChainLengthThreshold = 10;
   
   // Record values we are going to delete from this statepoint live set.
   // We can not di this in following loop due to iterator invalidation.