[X86] Disassembly Error, failed to decode prefetch instruction

[Mar3yZhang]

Work environment

Questions	Answers
OS/arch/bits	x86_64 Ubuntu 20.04
Architecture	x86_64
Source of Capstone	git clone, default on next branch.
Version/git commit	v6.0.0, d7be5f9

Instruction bytes giving faulty results

0x4a 0x0f 0x0d 0x28

Expected results

It should be:

prefetch [rax]

Steps to get the wrong result

With cstool:

$ ./cstool -d x64 "4a0f0d28"
ERROR: invalid assembly code

Additional Logs, screenshots, source code, configuration dump, ...

• Other x86 instruction decoders like Zydis and XED have no trouble with it.
• This issue is detected with a fully automatic decoder testing tool based on my research. Please add a Bug tag to this page if you verify it's a problem. It means a lot to me and my research. Thank you for your consideration😊!