Crash on use of out of scope binary view in Python

[D0ntPanic]

Version and Platform (required):

• Binary Ninja Version: 5.4.9605
• Edition: Ultimate
• OS: macOS
• OS Version: 26.4.1
• CPU Architecture: M5

Bug Description:
If you load a binary view with a with block, then access the variable holding the view outside the with block, the process crashes trying to read a null pointer in the FFI layer.

This is buggy Python code, but it shouldn't crash the process.

Steps To Reproduce:
Paste the following code in the Python console:

if True:
    with load("/bin/ls") as a:
        pass
    print(a)

The process should immediately crash with a null pointer access.

Expected Behavior:
Should get a Python exception instead of crashing the entire process.

[plafosse]

Looks like this could be fixed pretty easily by adding the following to binaryview. Also we'd have to update the setter and del to use _handle instead.

@property
def handle(self):
    if self._handle is None:
        raise ReferenceError("BinaryView has been closed")
    return self._handle