Remove the ref/value inconsistency in filter_decl_iterator.

filter_decl_iterator had a weird mismatch where both op* and op-> returned T*
making it difficult to generalize this filtering behavior into a reusable
library of any kind.

This change errs on the side of value, making op-> return T* and op* return
T&.

(reviewed by Richard Smith)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@155808 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ARCMigrate/Transforms.cpp b/lib/ARCMigrate/Transforms.cpp
index d342d1a..50bea95 100644
--- a/lib/ARCMigrate/Transforms.cpp
+++ b/lib/ARCMigrate/Transforms.cpp
@@ -472,8 +472,8 @@
   for (impl_iterator I = impl_iterator(DC->decls_begin()),
        E = impl_iterator(DC->decls_end()); I != E; ++I) {
     for (ObjCImplementationDecl::instmeth_iterator
-         MI = (*I)->instmeth_begin(),
-         ME = (*I)->instmeth_end(); MI != ME; ++MI) {
+         MI = I->instmeth_begin(),
+         ME = I->instmeth_end(); MI != ME; ++MI) {
       ObjCMethodDecl *MD = *MI;
       if (!MD->hasBody())
         continue;