Remove H[Reverse]PostOrderIterator and HInsertionOrderIterator.

Use range-based loops instead, introducing helper functions
ReverseRange() for iteration in reverse order in containers.
When the contents of the underlying container change inside
the loop, use an index-based loop that better exposes the
container data modifications, compared to the old iterator
interface that's hiding it which may lead to subtle bugs.

Test: m test-art-host
Change-Id: I2a4e6c508b854c37a697fc4b1e8423a8c92c5ea0
diff --git a/compiler/optimizing/select_generator.cc b/compiler/optimizing/select_generator.cc
index e409035..46d0d0e 100644
--- a/compiler/optimizing/select_generator.cc
+++ b/compiler/optimizing/select_generator.cc
@@ -76,8 +76,7 @@
   // Iterate in post order in the unlikely case that removing one occurrence of
   // the selection pattern empties a branch block of another occurrence.
   // Otherwise the order does not matter.
-  for (HPostOrderIterator it(*graph_); !it.Done(); it.Advance()) {
-    HBasicBlock* block = it.Current();
+  for (HBasicBlock* block : graph_->GetPostOrder()) {
     if (!block->EndsWithIf()) continue;
 
     // Find elements of the diamond pattern.