Indirectly dispatch all backtracking jumps through the same block.

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index fe9b484a41334cb18585c661e2f7275b7a3a855d..6f1e3af13f009dbf83b0c41cb6d6bbf4a13dcac3 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -110,7 +110,7 @@ class DefaultCompilationPipeline : public CompilationPipeline {
 class IrregexpCompilationPipeline : public DefaultCompilationPipeline {
  public:
   explicit IrregexpCompilationPipeline(Isolate* isolate)
-    : macro_assembler_(NULL),
+    : backtrack_goto_(NULL),
       isolate_(isolate) { }
 
   virtual void ParseFunction(ParsedFunction* parsed_function) {
@@ -127,7 +127,7 @@ class IrregexpCompilationPipeline : public DefaultCompilationPipeline {
         RegExpEngine::Compile(parsed_function->regexp_compile_data(),
                               parsed_function,
                               ic_data_array);
-    macro_assembler_ = result.macro_assembler;
+    backtrack_goto_ = result.backtrack_goto;
 
     // Allocate variables now that we know the number of locals.
     parsed_function->AllocateIrregexpVariables(result.num_stack_locals);
@@ -144,11 +144,11 @@ class IrregexpCompilationPipeline : public DefaultCompilationPipeline {
   }
 
   virtual void FinalizeCompilation() {
-    macro_assembler_->FinalizeBlockOffsetTable();
+    backtrack_goto_->ComputeOffsetTable(isolate_);
   }
 
  private:
-  IRRegExpMacroAssembler* macro_assembler_;
+  IndirectGotoInstr* backtrack_goto_;
   Isolate* isolate_;
 };