Add Semantic check for Flang OpenMP 4.5 - 2.7.1 Do Loop restrictions for Threadprivate.

Implementation of Do loop threadprivate check.

Files:

resolve-directives.cpp

Testcases:

omp-do04-positivecase.f90
omp-do04.f90

Reviewed by: Kiran Chandramohan @kiranchandramohan

Differential Revision: https://reviews.llvm.org/D96686