Indirectly dispatch all backtracking jumps through the same block.

runtime/vm/regexp.cc

 // Copyright (c) 2014, 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/regexp.h"
 
 #include "vm/dart_entry.h"
 #include "vm/regexp_assembler.h"
 #include "vm/regexp_ast.h"
 #include "vm/unibrow-inl.h"
@@ skipping 390 matching lines @@
   macro_assembler_->PushBacktrack(&fail);
   Trace new_trace;
   start->Emit(this, &new_trace);
   macro_assembler_->BindBlock(&fail);
   macro_assembler_->Fail();
   while (!work_list.is_empty()) {
     work_list.RemoveLast()->Emit(this, &new_trace);
   }
   if (reg_exp_too_big_) return IrregexpRegExpTooBig();
 
-  macro_assembler->FinalizeIndirectGotos();
+  macro_assembler->GenerateBacktrackBlock();
 
-  return RegExpEngine::CompilationResult(macro_assembler,
+  return RegExpEngine::CompilationResult(macro_assembler->backtrack_goto(),
                                          macro_assembler->graph_entry(),
                                          macro_assembler->num_blocks(),
                                          macro_assembler->num_stack_locals());
 }
 
 
 bool Trace::DeferredAction::Mentions(intptr_t that) {
   if (action_type() == ActionNode::CLEAR_CAPTURES) {
     Interval range = static_cast<DeferredClearCaptures*>(this)->range();
     return range.Contains(that);
@@ skipping 4739 matching lines @@
   CreateSpecializedFunction(isolate, regexp, kOneByteStringCid, owner);
   CreateSpecializedFunction(isolate, regexp, kTwoByteStringCid, owner);
   CreateSpecializedFunction(isolate, regexp, kExternalOneByteStringCid, owner);
   CreateSpecializedFunction(isolate, regexp, kExternalTwoByteStringCid, owner);
 
   return regexp.raw();
 }
 
 
 }  // namespace dart