libclang: factor out the frequent pattern static_cast<ASTUnit *>(TU->TUData)
into a getter cxtu::getASTUnit(TU)


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173585 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CXCursor.cpp b/tools/libclang/CXCursor.cpp
index 1a6a371..b7a5b30 100644
--- a/tools/libclang/CXCursor.cpp
+++ b/tools/libclang/CXCursor.cpp
@@ -810,7 +810,7 @@
   CXTranslationUnit TU = getCursorTU(Cursor);
   if (!TU)
     return 0;
-  return static_cast<ASTUnit *>(TU->TUData);
+  return cxtu::getASTUnit(TU);
 }
 
 CXTranslationUnit cxcursor::getCursorTU(CXCursor Cursor) {