[flang] Change TYPE(*) arrays passing convention

- Fix the BIND(C) assumed-shape case: TYPE(*) assumed shape are passed
  via CFI_cdesc_t according to Fortran 2018 standard 18.3.6 point 2 (5).
- Align the none BIND(C) case with the BIND(C) case. There is little
  point passing TYPE(*) assumed size via descriptor, use a simple
  address. C710 ensures there is no way the knowledge of the actual
  type will be required when manipulating the dummy.

Differential Revision: https://reviews.llvm.org/D148130