Make HForeignCode 'isAllocation' property available to optimization

pkg/compiler/lib/src/ssa/nodes.dart

Index: pkg/compiler/lib/src/ssa/nodes.dart
diff --git a/pkg/compiler/lib/src/ssa/nodes.dart b/pkg/compiler/lib/src/ssa/nodes.dart
index d7be40ce86e154d05bd3188e2e6d6c6c29920e6e..5e144dd3351e4609467286986fc03fa4a70a6d7b 100644
--- a/pkg/compiler/lib/src/ssa/nodes.dart
+++ b/pkg/compiler/lib/src/ssa/nodes.dart
@@ -842,6 +842,11 @@ abstract class HInstruction implements Spannable {
         && !canThrow();
   }
 
+  /// An instruction is an 'allocation' is it is the sole alias for an object.
+  /// This applies to to instructions that allocate new objects and can be
+  /// extended to methods that return other allocations without escaping them.
+  bool isAllocation() => false;
+
   /// Overridden by [HCheck] to return the actual non-[HCheck]
   /// instruction it checks against.
   HInstruction nonCheck() => this;
@@ -1751,6 +1756,10 @@ class HForeignCode extends HForeign {
 
   bool isJsStatement() => isStatement;
   bool canThrow() => throwBehavior.canThrow;
+
+  bool isAllocation() => nativeBehavior != null &&

[floitsch, 2015/04/13 07:54:56]

this is a getter name. -> should be a getter.
same is true for all the other predicates.

I guess we should do this cleanup in a separate CL.

[sra1, 2015/04/13 17:12:43]

Done.  At first I thought I might need an argument.

+      nativeBehavior.isAllocation &&
+      !canBeNull();
 }
 
 class HForeignNew extends HForeign {
@@ -1767,6 +1776,8 @@ class HForeignNew extends HForeign {
       : super(type, inputs);
 
   accept(HVisitor visitor) => visitor.visitForeignNew(this);
+
+  bool isAllocation() => true;
 }
 
 abstract class HInvokeBinary extends HInstruction {
@@ -2411,6 +2422,8 @@ class HLiteralList extends HInstruction {
   HLiteralList(List<HInstruction> inputs, TypeMask type) : super(inputs, type);
   toString() => 'literal list';
   accept(HVisitor visitor) => visitor.visitLiteralList(this);
+
+  bool isAllocation() => true;
 }
 
 /**