Implement clang_isUnexposed(), a predicate function to simplify filtering out
unexposed AST elements.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97985 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/CIndex/CIndex.exports b/tools/CIndex/CIndex.exports
index e68060b..5b95300 100644
--- a/tools/CIndex/CIndex.exports
+++ b/tools/CIndex/CIndex.exports
@@ -67,6 +67,7 @@
 _clang_isReference
 _clang_isStatement
 _clang_isTranslationUnit
+_clang_isUnexposed
 _clang_setUseExternalASTGeneration
 _clang_tokenize
 _clang_visitChildren