See https://github.com/llvm/llvm-project/pull/147168 for more info.

…ted. (#89998)" (#90250)

This partially reverts commit 7aedd7dc754c74a49fe84ed2640e269c25414087.

This change removes calls to the deprecated member functions. It does
not mark the functions deprecated yet and does not disable the
deprecation warning in TypeSwitch. This seems to cause problems with
MSVC.

This reverts commit 950b7ce0b88318f9099e9a7c9817d224ebdc6337.

This change is causing build failures on a bot
https://lab.llvm.org/buildbot/#/builders/216/builds/38157

See https://mlir.llvm.org/deprecation and
https://discourse.llvm.org/t/preferred-casting-style-going-forward.

For simplicity, lowering relies on semantics expansion of parent
components in designators.

This was not done in `call x%p()` where `p` is a procedure component
pointer of a parent component of `x`.

Do it and turn lowering TODO into a new lowering TODO for `call bar(x%type_bound_procedure)` (passing a tybe bound procedure is allowed as an extension, but lowering does not handle this extension yet. This is a lowering issue, will do in different patch).

Lower procedure pointer components, except in the context of structure
constructor (left TODO).

Procedure pointer components lowering share most of the lowering logic
of procedure poionters with the following particularities:
- They are components, so an hlfir.designate must be generated to
retrieve the procedure pointer address from its derived type base.
- They may have a PASS argument. While there is no dispatching as with
type bound procedure, special care must be taken to retrieve the derived
type component base in this case since semantics placed it in the
argument list and not in the evaluate::ProcedureDesignator.

These components also bring a new level of recursive MLIR types since a
fir.type may now contain a component with an MLIR function type where
one of the argument is the fir.type itself. This required moving the
"derived type in construction" stackto the converter so that the object
and function type lowering utilities share the same state (currently the
function type utilty would end-up creating a new stack when lowering its
arguments, leading to infinite loops). The BoxedProcedurePass also
needed an update to deal with this recursive aspect.

**Scope of the PR:**
1. Lowering global and local procedure pointer declaration statement
with explicit or implicit interface. The explicit interface can be from
an interface block, a module procedure or an internal procedure.
2. Lowering procedure pointer assignment, where the target procedure
could be external, module or internal procedures.
3. Lowering reference to procedure pointers so that it works end to end.

**PR notes:**
1. The first commit of the PR does not include testing. I would like to
collect some comments first, which may alter the output. Once I confirm
the implementation, I will add some testing as a follow up commit to
this PR.
2. No special handling of the host-associated entities when an internal
procedure is the target of a procedure pointer assignment in this PR.

**Implementation notes:**
1. The implementation is using the HLFIR path.
2. Flang currently uses `getUntypedBoxProcType` to get the
`fir::BoxProcType` for `ProcedureDesignator` when getting the address of
a procedure in order to pass it as an actual argument. This PR inherits
the same design decision for procedure pointer as the `fir::StoreOp`
requires the same memory type.

Note: this commit is actually resubmitting the original commit from
PR #70461 that was reverted. See PR #73221.

This reverts commit e07fec10ac208c2868a24c5c0be88e45778b297e.

This change appears to have broken following buildbots:
https://lab.llvm.org/buildbot/#/builders/176
https://lab.llvm.org/buildbot/#/builders/179
https://lab.llvm.org/buildbot/#/builders/184
https://lab.llvm.org/buildbot/#/builders/197
https://lab.llvm.org/buildbot/#/builders/198

All bots fails in testsuite where following tests seems broken:
(eg: https://lab.llvm.org/buildbot/#/builders/176/builds/7131)

test-suite::gfortran-regression-compile-regression__proc_ptr_46_f90.test
test-suite::gfortran-regression-compile-regression__proc_ptr_37_f90.test