Add a get_name implementation to BasicValue / BasicValueEnum

[pejato]

Is your feature request related to a problem? Please describe.

Hi @TheDan64, I've been working through Kaleidoscope's tutorial with inkwell and realized that I couldn't simply grab a parameter's name. e.g. I wanted to do something like the below

let the_fn: FunctionValue = ...
...
for param in the_fn.get_param_iter() {
  // I want to use param.get_name() here!
  self.named_values.insert(param.get_name(), param.as_any_value_enum());
}

Because function parameter's should be float valued in Kaleidoscope, I can simply check the param type with is_float_value() and then cast it with into_float_value() if that check succeeds, then I can use FloatValue's get_name(). i.e.,

let param_as_float: FloatValue = if param.is_float_value() {
    Ok(param.into_float_value())
} else {
    Err( ... )
}?;

let param_name = param_as_float
    .get_name()
    .to_str()
    ...

So it seems you can work around it, it just doesn't feel as ergonomic.

Describe the solution you'd like
I haven't thought about solutions here. I did see an old thread where get_name() was mentioned, so thought I'd re-raise it since it's been a few years.

[TheDan64]

If all possible BasicValueEnum variants support get_name, then I suppose this makes sense