libclang: Add clang_executeOnThread, for use in c-index-test (and only there,
preferably). Good thing c-index-test is written in C!!!!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@118223 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/libclang.darwin.exports b/tools/libclang/libclang.darwin.exports
index e9d40d0..7d5ae8b 100644
--- a/tools/libclang/libclang.darwin.exports
+++ b/tools/libclang/libclang.darwin.exports
@@ -25,6 +25,7 @@
 _clang_disposeTokens
 _clang_disposeTranslationUnit
 _clang_enableStackTraces
+_clang_executeOnThread
 _clang_equalCursors
 _clang_equalLocations
 _clang_equalTypes