Use one offsets table per generated irregexp matching function.

runtime/vm/regexp.h

 // 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.
 
 #ifndef VM_REGEXP_H_
 #define VM_REGEXP_H_
 
 #include "vm/assembler.h"
 #include "vm/intermediate_language.h"
 #include "vm/object.h"
@@ skipping 1354 matching lines @@
   bool contains_anchor;
   String& error;
   intptr_t capture_count;
 };
 
 
 class RegExpEngine: public AllStatic {
  public:
   struct CompilationResult {
     explicit CompilationResult(const char* error_message)
-        : macro_assembler(NULL),
-          graph_entry(NULL),
+        : graph_entry(NULL),
           num_blocks(-1),
           num_stack_locals(-1),
           error_message(error_message) {}
-    CompilationResult(IRRegExpMacroAssembler* macro_assembler,
-                      GraphEntryInstr* graph_entry,
+    CompilationResult(GraphEntryInstr* graph_entry,
                       intptr_t num_blocks,
                       intptr_t num_stack_locals)
-      : macro_assembler(macro_assembler),
-        graph_entry(graph_entry),
+      : graph_entry(graph_entry),
         num_blocks(num_blocks),
         num_stack_locals(num_stack_locals),
         error_message(NULL) {}
 
-    IRRegExpMacroAssembler* macro_assembler;
     GraphEntryInstr* graph_entry;
     const intptr_t num_blocks;
     const intptr_t num_stack_locals;
-
     const char* error_message;
   };
 
   static CompilationResult Compile(
       RegExpCompileData* input,
       const ParsedFunction* parsed_function,
       const ZoneGrowableArray<const ICData*>& ic_data_array);
 
   static RawJSRegExp* CreateJSRegExp(
       Isolate* isolate,
       const String& pattern,
       bool multi_line,
       bool ignore_case);
 
   static void DotPrint(const char* label, RegExpNode* node, bool ignore_case);
 };
 
 }  // namespace dart
 
 #endif  // VM_REGEXP_H_