Simplify map iterator clause assembly
- Split MLIR map syntax into separate map_entries(...) and map_iterated(...),
removing the custom MapEntryList parser/printer.
- Moved omp.target map_iterated out of TargetOpRegion
- it now prints before the target region instead of as map_iterated_entries(...) after the region.
- Renamed LLVMIR TODO helper to clause-style checkMap.
- Added DeclareMapperInfoOp builder from DeclareMapperInfoOperands
and updated Flang call sites so they do not need to spell out newly
added operands..