[Flang][OpenMP][NFC] Remove Fortran Evaluate Depedancy from Support (#198742)
Following #197442, FortranEvaluate was implicitly included in
OpenMP-utils.h which should be avoided to ensure front-end data
structures in the Optimizers can stop and restart pure MLIR source
without any side-data structures.
To ensure this is done, EntryBlockArgs has been stripped back to only
track vars, objects are now tracked within ObjectEntryBlockArgs in
Lowering as this is a more appropriate place for this information, and
the existing symbol tracking in EntryBlockArgsEntry was only used here.
This ensures FortranEvaluate is not needed within the Optimizers, and
objects can still be maintained when lowering. This enables better
referencing in Reduction Clauses, where previously context was being
lost for expressions such as ArrayElements.
See more: #197442
Assisted-by: Codex