X64: Fix bug in left-shift.

src/x64/assembler-x64.cc

 // Copyright 2009 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 561 matching lines @@
 
 void Assembler::shift_32(Register dst, int subcode) {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;
   emit_optional_rex_32(dst);
   emit(0xD3);
   emit_modrm(subcode, dst);
 }
 
 
+void Assembler::shift_32(Register dst, Immediate shift_amount, int subcode) {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  ASSERT(is_uint6(shift_amount.value_));  // illegal shift count
+  if (shift_amount.value_ == 1) {
+    emit_optional_rex_32(dst);
+    emit(0xD1);
+    emit_modrm(subcode, dst);
+  } else {
+    emit_optional_rex_32(dst);
+    emit(0xC1);
+    emit_modrm(subcode, dst);
+    emit(shift_amount.value_);
+  }
+}
+
+
 void Assembler::bt(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;
   emit_rex_64(src, dst);
   emit(0x0F);
   emit(0xA3);
   emit_operand(src, dst);
 }
 
 
@@ skipping 1584 matching lines @@
 bool BreakLocationIterator::IsDebugBreakAtReturn()  {
   UNIMPLEMENTED();
   return false;
 }
 
 void BreakLocationIterator::SetDebugBreakAtReturn()  {
   UNIMPLEMENTED();
 }
 
 } }  // namespace v8::internal