[llvm] Float2Int: Replace -float2int-max-integer-bw cl::opt with pass parameter (PR #223477)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> I'm not convinced we really want to have options like this as pass parameters, unless the pipeline actually wants to change that parameter.
> 
> Making it a pass parameter means that it's no longer easily possible to test an end-to-end compilation with a different value of the option by passing an `-mllvm` flag. While I think this particular option can probably just be deleted entirely, I believe that enabling that kind of experimentation is the primary purpose of having options of this type. (There are some people who will ask for an option to be added for every hardcoded optimization heuristic constant -- not something I agree with, but making them pass parameters would defeat the point.)

I think once all of these types of options are in pass parameters, we can come up something more systematic to set pass parameters via some new better structured command line flag 

https://github.com/llvm/llvm-project/pull/223477