Add forward iterator to iterate instructions inside a basic block.

vm/intermediate_language.cc

 // 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.
 
 #include "vm/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 509 matching lines @@
          successor()->IsBlockEntry());
   return successor() != NULL ? 1 : 0;
 }
 
 
 BlockEntryInstr* Instruction::SuccessorAt(intptr_t index) const {
   return successor()->AsBlockEntry();
 }
 
 
-Instruction* Instruction::RemoveFromGraph() {
-  ASSERT(!IsBlockEntry());
-  ASSERT(!IsBranch());
-  ASSERT(!IsThrow());
-  ASSERT(!IsReturn());
-  ASSERT(!IsReThrow());
-  ASSERT(previous() != NULL);
-  Instruction* next = successor();
-  previous()->set_successor(next);
-  if (next != NULL) {
-    if (!next->IsBlockEntry()) {
-      next->set_previous(previous());
-    } else {
-      // Removing the last instruction of a block.
-      // Update last_instruction of the current basic block.
-      Instruction* current = this;
-      while (!current->IsBlockEntry()) {
-        current = current->previous();
-      }
-      ASSERT(current->AsBlockEntry()->last_instruction() == this);
-      current->AsBlockEntry()->set_last_instruction(previous());
-    }
-  }
-  // Reset successor and previous instruction to indicate
-  // that the instruction is removed from the graph.
-  set_successor(NULL);
-  set_previous(NULL);
-  return next;
-}
-
-
 intptr_t GraphEntryInstr::SuccessorCount() const {
   return 1 + catch_entries_.length();
 }
 
 
 BlockEntryInstr* GraphEntryInstr::SuccessorAt(intptr_t index) const {
   if (index == 0) return normal_entry_;
   return catch_entries_[index - 1];
 }
 
@@ skipping 761 matching lines @@
   const ExternalLabel label(closure_function.ToCString(), stub.EntryPoint());
   compiler->GenerateCall(token_pos(), try_index(), &label,
                          PcDescriptors::kOther);
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 
 #undef __
 
 }  // namespace dart