[llvm] [RISCV][Disassemble] Ensure the comment stream of the disassembler is set. (PR #125962)

[via llvm-commits]

tedwoodward wrote:

> Is this the case? I don't think there is anything wrong with the input being debugged. I would consider this a bug of the debugger (assuming of course we decide to keep [1ea5ce6](https://github.com/llvm/llvm-project/commit/1ea5ce6335c7c0e040f70de16f1080546d242b69)).

The problem is when lldb instantiates the disassembler, if the target MCDisassembler code doesn't set CommentStream, it will be nullptr and the assert will fire, which takes down lldb. lldb doesn't control the CommentStream, but it not being set will cause lldb to crash. Maybe all the MCDisassemblers should set CommentStream, but that wasn't required in the past, so many don't.

Debuggers inherently deal with bad input all the time, and shouldn't die when that happens, but return an error to the user. 


https://github.com/llvm/llvm-project/pull/125962