[libclang] Introduce clang_Cursor_isNull and clang_Cursor_getTranslationUnit functions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140587 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/libclang.exports b/tools/libclang/libclang.exports
index d01bb07..71cd261 100644
--- a/tools/libclang/libclang.exports
+++ b/tools/libclang/libclang.exports
@@ -20,6 +20,7 @@
 clang_createIndex
 clang_createTranslationUnit
 clang_createTranslationUnitFromSourceFile
+clang_Cursor_getTranslationUnit
 clang_defaultCodeCompleteOptions
 clang_defaultDiagnosticDisplayOptions
 clang_defaultEditingTranslationUnitOptions