When inside a WHERE construct, the array constructor should be generated
within an hlfir.exactly_once region.

Fixes #130532

As described in
https://discourse.llvm.org/t/rfc-flang-representation-for-objects-inside-physical-storage/88026,
`[hl]fir.declare` should carry information about the layout
of COMMON/EQUIVALENCE variables within the physical storage.

This patch modifes Flang lowering to attach this information.

See #147168

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

Switch to common::visit more call sites.

Test plan: ninja check-all

The lowering produces fir.dummy_scope operation if the current
function has dummy arguments. Each hlfir.declare generated
for a dummy argument is then using the result of fir.dummy_scope
as its dummy_scope operand. This is only done for HLFIR.

I was not able to find a reliable way to identify dummy symbols
in `genDeclareSymbol`, so I added a set of registered dummy symbols
that is alive during the variables instantiation for the current
function. The set is initialized during the mapping of the dummy
argument symbols to their MLIR values. It is reset right after
all variables are instantiated - this is done to avoid generating
hlfir.declare operations with dummy_scope for the clones of
the dummy symbols (e.g. this happens with OpenMP privatization).

If this can be done in a cleaner way, please advise.

…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.