Warn/err on {nf} decorator for RCL/RCR

[LinuxCoder13]

So basically Intel APX says that NF=0 for RCL/RCR.
However Nasm 3.02 skips this check and compiles code which lead #UD for SDE64 -future

~$: nasm -felf64 input.asm -o a.o
~$: ld a.o -o a.out
~$: ../intel/sde/sde64 -future -- ./a.out
Illegal instruction at address = 401000: 62 f4 fc 0c c1 d1 0a 62 f4 fc 0c c1 d9 0a b8 
Image name: ~$/a.out
Offset in image: 0x1000
If you believe your application should attempt to execute
this illegal instruction (and others that may be present),
Then use this knob: -emit-illegal-insts 0
and this error message will be avoided.
Use -print-exception-details to get more details.

SDE ERROR: Illegal instruction at address = 401000: 62 f4 fc 0c c1 d1 0a 62 f4 fc 0c c1 d9 0a b8 
Image name: ~$/a.out
Offset in image: 0x1000
If you believe your application should attempt to execute
this illegal instruction (and others that may be present),
Then use this knob: -emit-illegal-insts 0
and this error message will be avoided.
Use -print-exception-details to get more details.

exception info: thread index = 0,context change reason = 0,exception code = 0x4
Backtrace:
==========
.text+0x000000000 at ~$/a.out+0x000401000 

~$:

Code:

section .text
global _start

_start:

    {nf} rcl rcx, 10
    {nf} rcr rcx, 10
    mov rax, 60 
    syscall

[ludloff]

Look for 'eshift'. Split it, to handle RCL/RCR differently, due to the 'no {NF}' rule.