Port and integrate the irregexp engine from V8

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 9608f2942820451e4951caf690c0869c8813b213..e8ff12c93a02577625b1496cbc70061666527460 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -7121,6 +7121,16 @@ class JSRegExp : public Instance {
     return raw_ptr()->num_bracket_expressions_;
   }
 
+  RawFunction* one_byte_function() const {
+    return raw_ptr()->one_byte_function_;
+  }
+  RawFunction* two_byte_function() const {
+    return raw_ptr()->two_byte_function_;
+  }
+
+  void set_one_byte_function(const Function& function);
+  void set_two_byte_function(const Function& function);
+
   void set_pattern(const String& pattern) const;
   void set_num_bracket_expressions(intptr_t value) const;
   void set_is_global() const { raw_ptr()->flags_ |= kGlobal; }