fix imul(reg, op, imm) emission on x64

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
diff --git a/src/x64/assembler-x64.cc b/src/x64/assembler-x64.cc
index 8cc53953e7a116d3b86ab67a1db47e257db35e0b..01103b234f961eddd5f02dde8bef3ac66addc12b 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -974,11 +974,13 @@ void Assembler::emit_imul(Register dst, const Operand& src, Immediate imm,
   emit_rex(dst, src, size);
   if (is_int8(imm.value_)) {
     emit(0x6B);
+    emit_operand(dst, src);
+    emit(imm.value_);
   } else {
     emit(0x69);
+    emit_operand(dst, src);
+    emitl(imm.value_);
   }
-  emit_operand(dst, src);
-  emit(imm.value_);
 }