Fix harmless HGraph verification failure after hoisting inlined bounds checks

src/hydrogen-bce.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/hydrogen-bce.h"
 
 namespace v8 {
 namespace internal {
 
 
@@ skipping 213 matching lines @@
                             HBoundsCheck* insert_before,
                             HInstruction* end_of_scan_range) {
     // index_raw can be HAdd(index_base, offset), HSub(index_base, offset),
     // HConstant(offset) or index_base directly.
     // In the latter case, no need to move anything.
     if (index_raw->IsAdd() || index_raw->IsSub()) {
       HArithmeticBinaryOperation* index =
           HArithmeticBinaryOperation::cast(index_raw);
       HValue* left_input = index->left();
       HValue* right_input = index->right();
+      HValue* context = index->context();
       bool must_move_index = false;
       bool must_move_left_input = false;
       bool must_move_right_input = false;
+      bool must_move_context = false;
       for (HInstruction* cursor = end_of_scan_range; cursor != insert_before;) {
         if (cursor == left_input) must_move_left_input = true;
         if (cursor == right_input) must_move_right_input = true;
+        if (cursor == context) must_move_context = true;
         if (cursor == index) must_move_index = true;
         if (cursor->previous() == NULL) {
           cursor = cursor->block()->dominator()->end();
         } else {
           cursor = cursor->previous();
         }
       }
       if (must_move_index) {
         index->Unlink();
         index->InsertBefore(insert_before);
       }
       // The BCE algorithm only selects mergeable bounds checks that share
       // the same "index_base", so we'll only ever have to move constants.
       if (must_move_left_input) {
         HConstant::cast(left_input)->Unlink();
         HConstant::cast(left_input)->InsertBefore(index);
       }
       if (must_move_right_input) {
         HConstant::cast(right_input)->Unlink();
         HConstant::cast(right_input)->InsertBefore(index);
       }
+      if (must_move_context) {
+        // Contexts are always constants.
+        HConstant::cast(context)->Unlink();
+        HConstant::cast(context)->InsertBefore(index);
+      }
     } else if (index_raw->IsConstant()) {
       HConstant* index = HConstant::cast(index_raw);
       bool must_move = false;
       for (HInstruction* cursor = end_of_scan_range; cursor != insert_before;) {
         if (cursor == index) must_move = true;
         if (cursor->previous() == NULL) {
           cursor = cursor->block()->dominator()->end();
         } else {
           cursor = cursor->previous();
         }
@@ skipping 188 matching lines @@
     if (data->FatherInDominatorTree()) {
       table_.Insert(data->Key(), data->FatherInDominatorTree(), zone());
     } else {
       table_.Delete(data->Key());
     }
     data = data->NextInBasicBlock();
   }
 }
 
 } }  // namespace v8::internal