[regexp] remove some dead code.

src/regexp/regexp-macro-assembler.h

 // Copyright 2012 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_H_
 #define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_
 
 #include "src/ast/ast.h"
 
 namespace v8 {
@@ skipping 86 matching lines @@
   virtual void CheckCharacterNotInRange(uc16 from,
                                         uc16 to,  // Both inclusive.
                                         Label* on_not_in_range) = 0;
 
   // The current character (modulus the kTableSize) is looked up in the byte
   // array, and if the found byte is non-zero, we jump to the on_bit_set label.
   virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) = 0;
 
   // Checks whether the given offset from the current position is before
   // the end of the string.  May overwrite the current character.
-  virtual void CheckPosition(int cp_offset, Label* on_outside_input) {
-    LoadCurrentCharacter(cp_offset, on_outside_input, true);
-  }
+  virtual void CheckPosition(int cp_offset, Label* on_outside_input) = 0;
   // Check whether a standard/default character class matches the current
   // character. Returns false if the type of special character class does
   // not have custom support.
   // May clobber the current loaded character.
-  virtual bool CheckSpecialCharacterClass(uc16 type,
-                                          Label* on_no_match) {
-    return false;
-  }
+  virtual bool CheckSpecialCharacterClass(uc16 type, Label* on_no_match) = 0;
   virtual void Fail() = 0;
   virtual Handle<HeapObject> GetCode(Handle<String> source) = 0;
   virtual void GoTo(Label* label) = 0;
   // Check whether a register is >= a given constant and go to a label if it
   // is.  Backtracks instead if the label is NULL.
   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge) = 0;
   // Check whether a register is < a given constant and go to a label if it is.
   // Backtracks instead if the label is NULL.
   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt) = 0;
   // Check whether a register is == to the current position and go to a
@@ skipping 116 matching lines @@
                         int output_size,
                         Isolate* isolate);
 };
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_