FoldingSet: Push the hash through FoldingSetTraits::Equals, so clients can use it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154496 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/FoldingSet.cpp b/lib/Support/FoldingSet.cpp
index e029970..c6282c6 100644
--- a/lib/Support/FoldingSet.cpp
+++ b/lib/Support/FoldingSet.cpp
@@ -265,15 +265,15 @@
 FoldingSetImpl::Node
 *FoldingSetImpl::FindNodeOrInsertPos(const FoldingSetNodeID &ID,
                                      void *&InsertPos) {
-  
-  void **Bucket = GetBucketFor(ID.ComputeHash(), Buckets, NumBuckets);
+  unsigned IDHash = ID.ComputeHash();
+  void **Bucket = GetBucketFor(IDHash, Buckets, NumBuckets);
   void *Probe = *Bucket;
   
   InsertPos = 0;
   
   FoldingSetNodeID TempID;
   while (Node *NodeInBucket = GetNextPtr(Probe)) {
-    if (NodeEquals(NodeInBucket, ID, TempID))
+    if (NodeEquals(NodeInBucket, ID, IDHash, TempID))
       return NodeInBucket;
     TempID.clear();