libclang: itroduce cxstring::createEmpty()

llvm-svn: 174174
diff --git a/clang/tools/libclang/CXSourceLocation.cpp b/clang/tools/libclang/CXSourceLocation.cpp
index bddb47b..afbac6d 100644
--- a/clang/tools/libclang/CXSourceLocation.cpp
+++ b/clang/tools/libclang/CXSourceLocation.cpp
@@ -187,7 +187,7 @@
 static void createNullLocation(CXString *filename, unsigned *line,
                                unsigned *column, unsigned *offset = 0) {
   if (filename)
-    *filename = createCXString("");
+    *filename = cxstring::createEmpty();
   if (line)
     *line = 0;
   if (column)