[Patch, Fortran] PR34186 -fdump-parse-tree fixes

[Dominique Dhumieres]

Just to be sure that we are looking at the same code.
The error comes from the orinial test in pr34186:

[ibook-dhum] f90/bug% cat > pr34186.f90
! { dg-do compile }
function func0(x) result(result_func0) bind(c)
  use, intrinsic :: iso_c_binding
  real(c_double) :: result_func0
  real(c_double), value, intent(in) :: x
  result_func0 = 1.0_c_double
end function func0

Dominique