Include PathV1.h in files that use it.

This is preparation for replacing Path.h with PathV2.h.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183781 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CIndexer.h b/tools/libclang/CIndexer.h
index 08162c5..6f000da 100644
--- a/tools/libclang/CIndexer.h
+++ b/tools/libclang/CIndexer.h
@@ -18,6 +18,7 @@
 #include "clang-c/Index.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/PathV1.h"
 #include <vector>
 
 namespace llvm {