Runtime support for the new stack maps for the opt compiler.

Now most of the methods supported by the compiler can be optimized,
instead of using the baseline.

Change-Id: I80ab36a34913fa4e7dd576c7bf55af63594dc1fa
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 490d345..f07029d 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -414,6 +414,10 @@
   env_uses_ = nullptr;
 }
 
+size_t HInstruction::EnvironmentSize() const {
+  return HasEnvironment() ? environment_->Size() : 0;
+}
+
 void HPhi::AddInput(HInstruction* input) {
   DCHECK(input->GetBlock() != nullptr);
   inputs_.Add(input);