The goal of the PR is to ensure that if module contains functions with
mutated signature (due to preprocessing of aggregate types), functions
still are going through re-creating of function type to preserve pointee
type information for arguments.
This fixes a bug when a module with (1) a function having aggregate
arguments and/or return, and (2) at least two functions with signatures
different only wrt. pointee types is translated so that one of two
similar functions gets an incorrect OpFunctionParameter type that is
different from the corresponding OpTypeFunction definition.
A reproducer is attached as a new test case.
