[clang] [analyzer] fix crash on binding to symbolic region with `void *` type (PR #107572)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

To me this solution seems to be a bit hacky -- I don't like that we need to scatter "handle `void *` as if it was `char *`" special cases in various parts of the analyzer (I vaguely recall that I have also seen similar hacks elsewhere).

I'd prefer solutions that are as generic as possible and ensure that `void *` is consistently handled like `char *` if that's what we want. (By the way, will the analyzer be able to use this `UnknownVal` bound to the `void *` pointer? If not, then just avoid the binding.)

These are not blocking issues, feel free to merge this commit to fix the crash (instead of waiting for a theoretically better solution).

https://github.com/llvm/llvm-project/pull/107572