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

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of ssa;
 
 /**
  * Replaces some instructions with specialized versions to make codegen easier.
  * Caches codegen information on nodes.
  */
@@ skipping 596 matching lines @@
     visitPostDominatorTree(graph);
   }
 
   /**
    * Check if a block has at least one statement other than
    * [instruction].
    */
   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,
     // then we will have to emit a statement for that last instruction.
     if (instruction != block.last
         && !identical(instruction, block.last.previous)) return true;
 
     // If one of the instructions in the block until [instruction] is
     // not generated at use site, then we will have to emit a
     // statement for it.
@@ skipping 127 matching lines @@
     }
 
     // If [thenInput] is defined in the first predecessor, then it is only used
     // by [phi] and can be generated at use site.
     if (identical(thenInput.block, end.predecessors[0])) {
       assert(thenInput.usedBy.length == 1);
       markAsGenerateAtUseSite(thenInput);
     }
   }
 }