Fix a bug when creating a HDeoptimization instruction.

We need to copy the environment, instead of just pointing
to an existing one. Otherwise, if the instruction that initially
holds the environemnt gets removed from the graph, any update
to an instruction in that environment will not be reflected in it.

bug:20058506

Change-Id: I2a62476d0851ecbc3707c0da395d8502ee437422
diff --git a/compiler/optimizing/nodes_test.cc b/compiler/optimizing/nodes_test.cc
index 4cf22d3..4e83ce5 100644
--- a/compiler/optimizing/nodes_test.cc
+++ b/compiler/optimizing/nodes_test.cc
@@ -50,7 +50,7 @@
   exit_block->AddInstruction(new (&allocator) HExit());
 
   HEnvironment* environment = new (&allocator) HEnvironment(&allocator, 1);
-  null_check->SetEnvironment(environment);
+  null_check->SetRawEnvironment(environment);
   environment->SetRawEnvAt(0, parameter);
   parameter->AddEnvUseAt(null_check->GetEnvironment(), 0);