How to preserve function parameters scopeness

[Ivan Butygin]

I want to extract function parameters types from declaration, 
remove some of them and construct new function pointer type from 
remaining types. Doing this in obvious way cause
parameters to lost their scope storage class: 
https://run.dlang.io/is/cQBFRW

I can extract and store scope information separately via 
ParameterStorageClassTuple but I don't know how to apply this 
information back when constructing new function pointer type. Of 
course I can CTFE string representation with full declaration and 
mixin it but it's ugly and probably slow to compile. Any ideas 
how to do this better?

I need this for my jit-bind template machinery, if someone 
interested
https://github.com/ldc-developers/ldc/blob/master/runtime/jit-rt/d/ldc/dynamic_compile.d#L120