[arm] Recognize SXTB, SXTH, UXTB and UXTH.

src/arm/assembler-arm.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1016 matching lines @@
 
   void bfi(Register dst, Register src, int lsb, int width,
            Condition cond = al);
 
   void pkhbt(Register dst, Register src1, const Operand& src2,
              Condition cond = al);
 
   void pkhtb(Register dst, Register src1, const Operand& src2,
              Condition cond = al);
 
-  void uxtb(Register dst, const Operand& src, Condition cond = al);
-
-  void uxtab(Register dst, Register src1, const Operand& src2,
+  void sxtb(Register dst, Register src, int rotate = 0, Condition cond = al);
+  void sxtab(Register dst, Register src1, Register src2, int rotate = 0,
+             Condition cond = al);
+  void sxth(Register dst, Register src, int rotate = 0, Condition cond = al);
+  void sxtah(Register dst, Register src1, Register src2, int rotate = 0,
              Condition cond = al);
 
-  void uxtb16(Register dst, const Operand& src, Condition cond = al);
+  void uxtb(Register dst, Register src, int rotate = 0, Condition cond = al);
+  void uxtab(Register dst, Register src1, Register src2, int rotate = 0,
+             Condition cond = al);
+  void uxtb16(Register dst, Register src, int rotate = 0, Condition cond = al);
+  void uxth(Register dst, Register src, int rotate = 0, Condition cond = al);
+  void uxtah(Register dst, Register src1, Register src2, int rotate = 0,
+             Condition cond = al);
 
   // Status register access instructions
 
   void mrs(Register dst, SRegister s, Condition cond = al);
   void msr(SRegisterFieldMask fields, const Operand& src, Condition cond = al);
 
   // Load/Store instructions
   void ldr(Register dst, const MemOperand& src, Condition cond = al);
   void str(Register src, const MemOperand& dst, Condition cond = al);
   void ldrb(Register dst, const MemOperand& src, Condition cond = al);
@@ skipping 614 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_