Same internal name used for functor parameters and their instantiations

[qsctr]

While implementing a solution to #1455, we found that functor instantiations use the same internal names as the corresponding parameters in the functor. Specifically, if we have

interface module I where
  x : [8]

module F where
  import interface I
  y = x + 1

module M where
  x = 2

module N = F { M }

then N::x reuses the exact same internal name as F::x (the full name being in this example F::I::x_5244) rather than a fresh name.

Currently, this does not present an immediate issue with evaluating expressions at the REPL, since the instantiated parameters are not accessible from outside of the instantiated module, and we can only ever look inside a single module in the REPL at once, so the REPL does not get confused by the duplicate names. However, the OrigName of the instantiated parameter would be wrong and could cause issues elsewhere.