Strip 'llvm' from 'llvm::Optional' uses.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175701 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/ClangDiagnosticsEmitter.cpp b/utils/TableGen/ClangDiagnosticsEmitter.cpp
index 448fb70..291eb75 100644
--- a/utils/TableGen/ClangDiagnosticsEmitter.cpp
+++ b/utils/TableGen/ClangDiagnosticsEmitter.cpp
@@ -291,7 +291,7 @@
 namespace {
 class InferPedantic {
   typedef llvm::DenseMap<const Record*,
-                         std::pair<unsigned, llvm::Optional<unsigned> > > GMap;
+                         std::pair<unsigned, Optional<unsigned> > > GMap;
 
   DiagGroupParentMap &DiagGroupParents;
   const std::vector<Record*> &Diags;