Add Semantic check for Flang OpenMP 4.5 - 2.15.3.2 and 2.15.3.3 shared and private clause

Semantic check to restrict the appearance of a variable that is part of another variable
 (as an array or structure element) in a PRIVATE or SHARED clause.

Test Cases:

omp-parallel-private01.f90
omp-parallel-private02.f90
omp-parallel-private03.f90
omp-parallel-private04.f90
omp-parallel-shared01.f90
omp-parallel-shared02.f90
omp-parallel-shared03.f90
omp-parallel-shared04.f90

Reviewed by: Kiran Chandramohan @kiranchandramohan , Valentin Clement @clementval

Differential Revision: https://reviews.llvm.org/D89395