dart2js cps: Insert bounds check for removeLast() -> pop() optimization.

pkg/compiler/lib/src/cps_ir/type_propagation.dart

Index: pkg/compiler/lib/src/cps_ir/type_propagation.dart
diff --git a/pkg/compiler/lib/src/cps_ir/type_propagation.dart b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
index 1ac163ee538b0732f31819e3dfb1f7c485a61acb..b185bc70b8cc801ba4e71076c7322d04c8898d98 100644
--- a/pkg/compiler/lib/src/cps_ir/type_propagation.dart
+++ b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
@@ -1230,6 +1230,14 @@ class TransformingVisitor extends LeafVisitor {
         }
         if (!isExtendable) return false;
         CpsFragment cps = new CpsFragment(sourceInfo);
+        Primitive length = cps.letPrim(new GetLength(list));
+        Primitive isEmpty = cps.applyBuiltin(
+            BuiltinOperator.StrictEq,
+            [length, cps.makeZero()]);
+        CpsFragment fail = cps.ifTruthy(isEmpty);
+        fail.invokeStaticThrower(
+            backend.getThrowIndexOutOfBoundsError(),
+            [list, fail.makeConstant(new IntConstantValue(-1))]);
         Primitive removedItem = cps.invokeBuiltin(BuiltinMethod.Pop,
             list,
             <Primitive>[],