support disassembling bytes from memoryview

[huettenhain]

Recreation of #1758 relative to the next branch.

[kabeor]

could you provide a testcase for this？

[kabeor]

@huettenhain I tried to verify this PR with following script

(a part of test_basic.py)

            md = Cs(arch, mode)
            code = memoryview(code)  # added this to check if memoryview work

            if syntax is not None:
                md.syntax = syntax

            for insn in md.disasm(code, 0x1000):
                print("0x%x:\t%s\t%s" % (insn.address, insn.mnemonic, insn.op_str))

but get this issue

File "capstone\bindings\python\capstone\__init__.py", line 1103, in disasm
    code = ctypes.byref(ctypes.c_char.from_buffer(code))
TypeError: underlying buffer is not writable

I think you should fix the compatibility of memoryview and ctypes

[huettenhain]

Hey! Sorry for the delay. Indeed I was not aware that ctypes would require the buffer to be writable. I think it might be best to simply include this as a check, I'll update the PR soon.

[huettenhain]

Hey @kabeor I didn't manage to build this locally, otherwise I would have tested it myself. I updated the PR so that it should work on any writable buffer type, including bytearray and memoryview.

[kabeor]

@huettenhain I tried to write a test case to verify your PR, but it didn't work. Can you write a test case function in bindings/python/test_basic.py?

[huettenhain]

I added a test and fixed one remaining bug in the code.

[kabeor]

Test confirmed. Thanks for your contribution.