[libclang] Move CursorVisitor to its own header.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143639 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/Index_Internal.h b/tools/libclang/Index_Internal.h
index df54d7c..2d42cb8 100644
--- a/tools/libclang/Index_Internal.h
+++ b/tools/libclang/Index_Internal.h
@@ -40,4 +40,16 @@
 
 #endif // !__has_feature(blocks)
 
+/// \brief The result of comparing two source ranges.
+enum RangeComparisonResult {
+  /// \brief Either the ranges overlap or one of the ranges is invalid.
+  RangeOverlap,
+
+  /// \brief The first range ends before the second range starts.
+  RangeBefore,
+
+  /// \brief The first range starts after the second range ends.
+  RangeAfter
+};
+
 #endif