[llvm] [llvm-cxxfilt] Added the option --no-params (PR #75348)

[Dmitry Vasilyev via llvm-commits]

slydiman wrote:

> The `--no-params` option doesn't just not demangle the parameters, it omits the enclosing parentheses entirely. I think this is important behaviour that we need to replicate.

Ok, agreed. Note the `--no-params` option omits the return type too. I have updated the patch to fully match this behavior.

https://github.com/llvm/llvm-project/pull/75348