[flang] Catch I/O of bad derived type at compile time

Derived types with allocatable and pointer components cannot
be used in I/O data transfer statements unless they have defined
I/O procedures available (as type-bound or regular generics).
These cases are caught as errors by the I/O runtime library,
but it would be better if they were flagged during compilation.

(Address comment in review: don't use explicit name string lengths.)

Differential Revision: https://reviews.llvm.org/D120675