Ensure environment is ready when populating loop.

Rationale:
OSR requires the suspend check to already have an environment,
albeit just for testing irreducible loops. This CL fixes the
omission. Note, the error is spurious on OSR and writing a
unit or regression test for this is hard.

Test: test-art-host
Bug: 36950873
Change-Id: Ica89e18e10deb438dead79e2cc40dd00a60b529f
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 5617e4b..e71fea9 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -2380,11 +2380,13 @@
   MakeRoomFor(&reverse_post_order_, 1, index_of_body - 1);
   reverse_post_order_[index_of_body] = new_body;
 
-  // Add gotos and suspend check (client must add conditional in header and copy environment).
+  // Add gotos and suspend check (client must add conditional in header).
   new_pre_header->AddInstruction(new (arena_) HGoto());
   HSuspendCheck* suspend_check = new (arena_) HSuspendCheck(header->GetDexPc());
   new_header->AddInstruction(suspend_check);
   new_body->AddInstruction(new (arena_) HGoto());
+  suspend_check->CopyEnvironmentFromWithLoopPhiAdjustment(
+      loop->GetSuspendCheck()->GetEnvironment(), header);
 
   // Update loop information.
   new_header->AddBackEdge(new_body);