Include llvm::Optional in clang/Basic/LLVM.h

Post-commit CR feedback from Jordan Rose regarding r175594.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175679 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp b/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
index 27692fe..5e4b824 100644
--- a/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
+++ b/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
@@ -110,12 +110,12 @@
 
   SVal extentBegin = computeExtentBegin(svalBuilder, rawOffset.getRegion());
   
-  if (llvm::Optional<NonLoc> NV = extentBegin.getAs<NonLoc>()) {
+  if (Optional<NonLoc> NV = extentBegin.getAs<NonLoc>()) {
     SVal lowerBound =
         svalBuilder.evalBinOpNN(state, BO_LT, rawOffset.getByteOffset(), *NV,
                                 svalBuilder.getConditionType());
 
-    llvm::Optional<NonLoc> lowerBoundToCheck = lowerBound.getAs<NonLoc>();
+    Optional<NonLoc> lowerBoundToCheck = lowerBound.getAs<NonLoc>();
     if (!lowerBoundToCheck)
       return;
     
@@ -147,7 +147,7 @@
                                 extentVal.castAs<NonLoc>(),
                                 svalBuilder.getConditionType());
   
-    llvm::Optional<NonLoc> upperboundToCheck = upperbound.getAs<NonLoc>();
+    Optional<NonLoc> upperboundToCheck = upperbound.getAs<NonLoc>();
     if (!upperboundToCheck)
       break;