[flang][OpenMP] Enhance parser support for atomic construct to OpenMP 5.0
This patch enhances parser support for atomic construct to OpenMP 5.0.
2.17.7 atomic -> ATOMIC [clause [,]] atomic-clause [[,] clause] |
ATOMIC [clause] clause -> memory-order-clause | HINT(hint-expression) memory-order-clause -> SEQ_CST | ACQ_REL | RELEASE | ACQUIRE | RELAXED atomic-clause -> READ | WRITE | UPDATE | CAPTURE
The patch includes code changes and testcase modifications.
Reviewed By: DavidTruby, kiranchandramohan, sameeranjoshi
Differential Revision: https://reviews.llvm.org/D82931