Add Semantic checks for OpenMP 4.5 - 2.7.4 Workshare Construct.
- The structured block in a workshare construct may consist of only
scalar or array assignments, forall or where statements,
forall, where, atomic, critical or parallel constructs.
- All array assignments, scalar assignments, and masked array
assignments must be intrinsic assignments.
- The construct must not contain any user defined function calls unless
the function is ELEMENTAL.
Test cases : omp-workshare03.f90, omp-workshare04.f90, omp-workshare05.f90
Resolve test cases (omp-workshare01.f90 and omp-workshare02.f90) marked as XFAIL
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D93091