[flang][driver] Add `-fno-analyzed-objects-for-unparse`
This patch adds a new option for the new Flang driver:
`-fno-analyzed-objects-for-unparse`. The semantics are similar to
`-funparse-typed-exprs-to-f18-fc` from `f18`. For consistency, the
latter is replaced with `-fno-analyzed-objects-for-unparse`.
The new option controls the behaviour of the unparser (i.e. the action
corresponding to `-fdebug-unparse`). The default behaviour is to use the
analyzed objects when unparsing. The new flag can be used to turn this
off, so that the original parse-tree objects are used. The analyzed
objects are generated during the semantic checks [1].
This patch also updates the semantics of
`-fno-analyzed-objects-for-unparse`/`-funparse-typed-exprs-to-f18-fc`
in `f18`, so that this flag is always taken into account when `Unparse`
is used (this way the semantics in `f18` and `flang-new` are identical).
The added test file is based on example from Peter Steinfeld.
[1]
https://github.com/llvm/llvm-project/blob/main/flang/docs/Semantics.md
Differential Revision: https://reviews.llvm.org/D103612