code: def call(self, fn, args, name='', cconv=None, tail=False, fastmath=()):
          
          inst = instructions.CallInstr(self.block, fn, args, name=name,
                                        cconv=cconv, tail=tail, fastmath=fastmath)
          self._insert(inst)
          return inst
docs: Call function *fn* with *args*:
              name = fn(args...)