[regexp] do not include irregexp interpreter by default.

src/regexp/regexp-macro-assembler-irregexp-inl.h

 // Copyright 2008-2009 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_INL_H_
 #define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_INL_H_
 
+#ifdef V8_INTERPRETED_REGEXP
+
 #include "src/ast/ast.h"
 #include "src/regexp/bytecodes-irregexp.h"
 
 namespace v8 {
 namespace internal {
 
-#ifdef V8_INTERPRETED_REGEXP
-
 void RegExpMacroAssemblerIrregexp::Emit(uint32_t byte,
                                         uint32_t twenty_four_bits) {
   uint32_t word = ((twenty_four_bits << BYTECODE_SHIFT) | byte);
   DCHECK(pc_ <= buffer_.length());
   if (pc_  + 3 >= buffer_.length()) {
     Expand();
   }
   *reinterpret_cast<uint32_t*>(buffer_.start() + pc_) = word;
   pc_ += 4;
 }
@@ skipping 21 matching lines @@
 
 void RegExpMacroAssemblerIrregexp::Emit32(uint32_t word) {
   DCHECK(pc_ <= buffer_.length());
   if (pc_ + 3 >= buffer_.length()) {
     Expand();
   }
   *reinterpret_cast<uint32_t*>(buffer_.start() + pc_) = word;
   pc_ += 4;
 }
 
-#endif  // V8_INTERPRETED_REGEXP
-
 }  // namespace internal
 }  // namespace v8
 
+#endif  // V8_INTERPRETED_REGEXP
+
 #endif  // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_INL_H_