[llvm-symbolizer] Add back --version and add a -v alias

The switch from llvm::cl to OptTable (D83530) dropped --version, which
is needed by some users.

This patch also adds a -v alias, which is available in GNU addr2line.

The version dumping is similar to llvm-objcopy --version (exotic):

```
llvm-symbolizer
LLVM (http://llvm.org/):
  LLVM version 12.0.0git
  Optimized build with assertions.
  Default target: x86_64-unknown-linux-gnu
  Host CPU: skylake-avx512
```

Reviewed By: dyung, jhenderson

Differential Revision: https://reviews.llvm.org/D85624