IR: Make temporary nodes distinct

Change the return of `MDNode::isDistinct()` for `MDNode::getTemporary()`
to `true`.  They aren't uniqued.

llvm-svn: 225646
diff --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
index 2dd54e7..a09cc9c 100644
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -269,6 +269,12 @@
   ASSERT_EQ(Empty, MDNode::get(Context, None));
 }
 
+TEST_F(MDNodeTest, TempIsDistinct) {
+  MDNode *T = MDNode::getTemporary(Context, None);
+  EXPECT_TRUE(T->isDistinct());
+  MDNode::deleteTemporary(T);
+}
+
 TEST_F(MDNodeTest, getDistinctWithUnresolvedOperands) {
   // temporary !{}
   MDNodeFwdDecl *Temp = MDNode::getTemporary(Context, None);