Revert of [x64] Zero/sign-extend loads to 64-bit registers.

src/compiler/x64/instruction-codes-x64.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_X64_INSTRUCTION_CODES_X64_H_
 #define V8_COMPILER_X64_INSTRUCTION_CODES_X64_H_
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 99 matching lines @@
   V(AVXFloat64Add)                 \
   V(AVXFloat64Sub)                 \
   V(AVXFloat64Mul)                 \
   V(AVXFloat64Div)                 \
   V(AVXFloat64Abs)                 \
   V(AVXFloat64Neg)                 \
   V(AVXFloat32Abs)                 \
   V(AVXFloat32Neg)                 \
   V(X64Movsxbl)                    \
   V(X64Movzxbl)                    \
-  V(X64Movsxbq)                    \
-  V(X64Movzxbq)                    \
   V(X64Movb)                       \
   V(X64Movsxwl)                    \
   V(X64Movzxwl)                    \
-  V(X64Movsxwq)                    \
-  V(X64Movzxwq)                    \
   V(X64Movw)                       \
   V(X64Movl)                       \
   V(X64Movsxlq)                    \
   V(X64Movq)                       \
   V(X64Movsd)                      \
   V(X64Movss)                      \
   V(X64BitcastFI)                  \
   V(X64BitcastDL)                  \
   V(X64BitcastIF)                  \
   V(X64BitcastLD)                  \
@@ skipping 38 matching lines @@
   V(M1I)  /* [      %r2*1 + K] */      \
   V(M2I)  /* [      %r2*2 + K] */      \
   V(M4I)  /* [      %r2*4 + K] */      \
   V(M8I)  /* [      %r2*8 + K] */
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_X64_INSTRUCTION_CODES_X64_H_