Rename invariant.group.barrier to launder.invariant.group

Summary:
This is one of the initial commit of "RFC: Devirtualization v2" proposal:
https://docs.google.com/document/d/16GVtCpzK8sIHNc2qZz6RN8amICNBtvjWUod2SujZVEo/edit?usp=sharing

Reviewers: rsmith, amharc, kuhar, sanjoy

Subscribers: arsenm, nhaehnle, javed.absar, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45111

llvm-svn: 331448
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 8729db4..3e8fd4eb 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -1668,7 +1668,7 @@
       InsertedInsts.insert(ExtVal);
       return true;
     }
-    case Intrinsic::invariant_group_barrier:
+    case Intrinsic::launder_invariant_group:
       II->replaceAllUsesWith(II->getArgOperand(0));
       II->eraseFromParent();
       return true;