[turbofan] Recognize sign extension of 8-bit and 16-bit values on arm64.

src/compiler/arm64/instruction-codes-arm64.h

 // Copyright 2014 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_COMPILER_ARM64_INSTRUCTION_CODES_ARM64_H_
 #define V8_COMPILER_ARM64_INSTRUCTION_CODES_ARM64_H_
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 47 matching lines @@
   V(Arm64Neg32)                    \
   V(Arm64Lsl)                      \
   V(Arm64Lsl32)                    \
   V(Arm64Lsr)                      \
   V(Arm64Lsr32)                    \
   V(Arm64Asr)                      \
   V(Arm64Asr32)                    \
   V(Arm64Ror)                      \
   V(Arm64Ror32)                    \
   V(Arm64Mov32)                    \
+  V(Arm64Sxtb32)                   \
+  V(Arm64Sxth32)                   \
   V(Arm64Sxtw)                     \
   V(Arm64Ubfx)                     \
   V(Arm64Ubfx32)                   \
   V(Arm64Tbz)                      \
   V(Arm64Tbz32)                    \
   V(Arm64Tbnz)                     \
   V(Arm64Tbnz32)                   \
   V(Arm64Cbz32)                    \
   V(Arm64Cbnz32)                   \
   V(Arm64Claim)                    \
@@ skipping 53 matching lines @@
   V(Operand2_R_LSL_I) /* %r0 LSL K */   \
   V(Operand2_R_LSR_I) /* %r0 LSR K */   \
   V(Operand2_R_ASR_I) /* %r0 ASR K */   \
   V(Operand2_R_ROR_I) /* %r0 ROR K */
 
 }  // namespace internal
 }  // namespace compiler
 }  // namespace v8
 
 #endif  // V8_COMPILER_ARM64_INSTRUCTION_CODES_ARM64_H_