[C++11] Replacing iterators redecls_begin() and redecls_end() with iterator_range redecls(). Updating all of the usages of the iterators with range-based for loops, which allows the begin/end forms to be removed entirely.

llvm-svn: 203179
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 2ca4911..00692df 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -313,7 +313,7 @@
     return true;
 
   // Check redeclarations.
-  for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I)
+  for (auto I : redecls())
     if (I->Referenced)
       return true;