[libclang] Introduce clang_Cursor_getSpellingNameRange().

It retrieves a source range for a piece that forms the cursors spelling name.
Most of the times there is only one range for the complete spelling but for
objc methods and objc message expressions, there are multiple pieces for each
selector identifier.

Part of rdar://11113120

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153775 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang-c/Index.h b/include/clang-c/Index.h
index 54f461b..a65bb63 100644
--- a/include/clang-c/Index.h
+++ b/include/clang-c/Index.h
@@ -2904,6 +2904,21 @@
 CINDEX_LINKAGE CXString clang_getCursorSpelling(CXCursor);
 
 /**
+ * \brief Retrieve a range for a piece that forms the cursors spelling name.
+ * Most of the times there is only one range for the complete spelling but for
+ * objc methods and objc message expressions, there are multiple pieces for each
+ * selector identifier.
+ * 
+ * \param pieceIndex the index of the spelling name piece. If this is greater
+ * than the actual number of pieces, it will return a NULL (invalid) range.
+ *  
+ * \param options Reserved.
+ */
+CINDEX_LINKAGE CXSourceRange clang_Cursor_getSpellingNameRange(CXCursor,
+                                                          unsigned pieceIndex,
+                                                          unsigned options);
+
+/**
  * \brief Retrieve the display name for the entity referenced by this cursor.
  *
  * The display name contains extra information that helps identify the cursor,