[flang][openmp] Check clauses allowed semantic with tablegen generated map

Summary:
This patch is enabling the generation of clauses enum sets for semantics check in Flang through
tablegen. Enum sets and directive - sets map is generated by the new tablegen infrsatructure for OpenMP
and other directive languages.
The semantic checks for OpenMP are modified to use this newly generated map.

Reviewers: DavidTruby, sscalpone, kiranchandramohan, ichoyjx, jdoerfert

Reviewed By: DavidTruby, ichoyjx

Subscribers: mgorny, yaxunl, hiraditya, guansong, sstefan1, aaron.ballman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83326