Rewrite for-in loop as indexing loop for JavaScript indexable arrays

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

Index: pkg/compiler/lib/src/ssa/codegen_helpers.dart
diff --git a/pkg/compiler/lib/src/ssa/codegen_helpers.dart b/pkg/compiler/lib/src/ssa/codegen_helpers.dart
index 531f3233a2eef8a2b005180af9204b490bf80a54..e6bf13d27619c7f4deb82416127d26deeda8c817 100644
--- a/pkg/compiler/lib/src/ssa/codegen_helpers.dart
+++ b/pkg/compiler/lib/src/ssa/codegen_helpers.dart
@@ -614,7 +614,9 @@ class SsaConditionMerger extends HGraphVisitor {
   bool hasAnyStatement(HBasicBlock block, HInstruction instruction) {
     // If [instruction] is not in [block], then if the block is not
     // empty, we know there will be a statement to emit.
-    if (!identical(instruction.block, block)) return !identical(block.last, block.first);
+    if (!identical(instruction.block, block)) {
+      return !identical(block.last, block.first);
+    }
 
     // If [instruction] is not the last instruction of the block
     // before the control flow instruction, or the last instruction,