Added MD_invariant_group to LLVMContext

http://reviews.llvm.org/D12926

llvm-svn: 247931
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index d0c8fb9..8faa35b 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -4836,6 +4836,6 @@
 }
 
 void CodeGenPrepare::stripInvariantGroupMetadata(Instruction &I) {
-  if (auto *InvariantMD = I.getMetadata("invariant.group"))
+  if (auto *InvariantMD = I.getMetadata(LLVMContext::MD_invariant_group))
     I.dropUnknownNonDebugMetadata(InvariantMD->getMetadataID());
 }