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.exports b/tools/libclang/libclang.exports
index fd96be3..da7f9c8 100644
--- a/tools/libclang/libclang.exports
+++ b/tools/libclang/libclang.exports
@@ -25,6 +25,7 @@
 clang_disposeTokens
 clang_disposeTranslationUnit
 clang_enableStackTraces
+clang_executeOnThread
 clang_equalCursors
 clang_equalLocations
 clang_equalTypes