Add a parent environment to HEnvironment.

This code has no functionality change. It adds a placeholder
for chaining inlined frames.

Change-Id: I5ec57335af76ee406052345b947aad98a6a4423a
diff --git a/compiler/optimizing/graph_test.cc b/compiler/optimizing/graph_test.cc
index 50398b4..59d5092 100644
--- a/compiler/optimizing/graph_test.cc
+++ b/compiler/optimizing/graph_test.cc
@@ -73,7 +73,7 @@
   ArenaPool pool;
   ArenaAllocator allocator(&pool);
 
-  HGraph* graph = new (&allocator) HGraph(&allocator);
+  HGraph* graph = CreateGraph(&allocator);
   HBasicBlock* entry_block = createEntryBlock(graph, &allocator);
   HBasicBlock* if_block = createIfBlock(graph, &allocator);
   HBasicBlock* if_true = createGotoBlock(graph, &allocator);
@@ -108,7 +108,7 @@
   ArenaPool pool;
   ArenaAllocator allocator(&pool);
 
-  HGraph* graph = new (&allocator) HGraph(&allocator);
+  HGraph* graph = CreateGraph(&allocator);
   HBasicBlock* entry_block = createEntryBlock(graph, &allocator);
   HBasicBlock* if_block = createIfBlock(graph, &allocator);
   HBasicBlock* if_false = createGotoBlock(graph, &allocator);
@@ -143,7 +143,7 @@
   ArenaPool pool;
   ArenaAllocator allocator(&pool);
 
-  HGraph* graph = new (&allocator) HGraph(&allocator);
+  HGraph* graph = CreateGraph(&allocator);
   HBasicBlock* entry_block = createEntryBlock(graph, &allocator);
   HBasicBlock* if_block = createIfBlock(graph, &allocator);
   HBasicBlock* return_block = createReturnBlock(graph, &allocator);
@@ -178,7 +178,7 @@
   ArenaPool pool;
   ArenaAllocator allocator(&pool);
 
-  HGraph* graph = new (&allocator) HGraph(&allocator);
+  HGraph* graph = CreateGraph(&allocator);
   HBasicBlock* entry_block = createEntryBlock(graph, &allocator);
   HBasicBlock* if_block = createIfBlock(graph, &allocator);
   HBasicBlock* return_block = createReturnBlock(graph, &allocator);
@@ -213,7 +213,7 @@
   ArenaPool pool;
   ArenaAllocator allocator(&pool);
 
-  HGraph* graph = new (&allocator) HGraph(&allocator);
+  HGraph* graph = CreateGraph(&allocator);
   HBasicBlock* entry_block = createEntryBlock(graph, &allocator);
   HBasicBlock* first_if_block = createIfBlock(graph, &allocator);
   HBasicBlock* if_block = createIfBlock(graph, &allocator);
@@ -252,7 +252,7 @@
   ArenaPool pool;
   ArenaAllocator allocator(&pool);
 
-  HGraph* graph = new (&allocator) HGraph(&allocator);
+  HGraph* graph = CreateGraph(&allocator);
   HBasicBlock* entry_block = createEntryBlock(graph, &allocator);
   HBasicBlock* first_if_block = createIfBlock(graph, &allocator);
   HBasicBlock* if_block = createIfBlock(graph, &allocator);
@@ -288,7 +288,7 @@
   ArenaPool pool;
   ArenaAllocator allocator(&pool);
 
-  HGraph* graph = new (&allocator) HGraph(&allocator);
+  HGraph* graph = CreateGraph(&allocator);
   HBasicBlock* block = createGotoBlock(graph, &allocator);
   HInstruction* got = block->GetLastInstruction();
   ASSERT_TRUE(got->IsControlFlow());