RegionInfo: use a range-based for loop [NFCI]

[nhaehnle]

Summary

Change-Id: I9985d72191a2b0680195032acf8a14ad2ba954ed

[nhaehnle]

Seems trivial enough, and there doesn't really seem to be an owner of this code...

[dblaikie]

Yeah, looks good - generally no need to send things like this sort of cleanup for review (can be committed directly/for post-commit review).

I guess this could even be replaced by something like:

return llvm::none_of(*entrySuccs, [&](BlockT* successor) {
  return successor != exit && successor != entry;
});

Not sure if that's better/more readable or not, up to you.

llvm/include/llvm/Analysis/RegionInfoImpl.h

 //===- RegionInfoImpl.h - SESE region detection analysis --------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // Detects single entry single exit regions in the control flow graph.
bool RegionInfoBase<Tr>::isRegion(BlockT *entry, BlockT *exit) const {
 
   using DST = typename DomFrontierT::DomSetType;
 
   DST *entrySuccs = &DF->find(entry)->second;
 
   // Exit is the header of a loop that contains the entry. In this case,
   // the dominance frontier must only contain the exit.
   if (!DT->dominates(entry, exit)) {
-    for (typename DST::iterator SI = entrySuccs->begin(),
-                                SE = entrySuccs->end();
-         SI != SE; ++SI) {
-      if (*SI != exit && *SI != entry)
+    for (BlockT *successor : *entrySuccs) {
+      if (successor != exit && successor != entry)
         return false;
     }
 
     return true;
   }
 
   DST *exitSuccs = &DF->find(exit)->second;