libclang: itroduce cxstring::createEmpty()


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174174 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CXString.h b/tools/libclang/CXString.h
index 5078a42..0495ee9 100644
--- a/tools/libclang/CXString.h
+++ b/tools/libclang/CXString.h
@@ -25,6 +25,9 @@
 
 struct CXStringBuf;
 
+/// \brief Create a CXString object for an empty "" string.
+CXString createEmpty();
+
 /// \brief Create a CXString object for an NULL string.
 CXString createNull();