[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/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 9bfdc5f..fe62ab4 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1450,10 +1450,8 @@
       }
       // Check for redefinitions due to other instantiations of this or
       // a similar friend function.
-      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
-                                           REnd = Function->redecls_end();
-                R != REnd; ++R) {
-        if (*R == Function)
+      else for (auto R : Function->redecls()) {
+        if (R == Function)
           continue;
 
         // If some prior declaration of this function has been used, we need