This patch adds parser nodes for each indivudual section in sections
construct. This should help with the translation to FIR. `!$omp section`
was not recognized as a construct and hence needed special handling.
`OpenMPSectionsConstruct` contains a list of `OpenMPConstruct`. Each
such `OpenMPConstruct` wraps an `OpenMPSectionConstruct`
(section, not sections). An `OpenMPSectionConstruct` is a wrapper around
a `Block`.
Reviewed By: kiranchandramohan, peixin
Differential Revision: https://reviews.llvm.org/D121680
Currently, everything that includes "flang/Parser/parse-tree.h" in Flang
depends on the `gen_acc` and `gen_omp` CMake targets (these targets
generate include files that are used in "parse-tree.h"). The examples in
Flang do use this header file and hence also depend on
`gen_acc`/`gen_omp`. This patch updates relevant CMake scripts
accordingly.
I've also taken the liberty to rename some of the example files so that
their names follow LLVM's coding guidelines.
Differential Revision: https://reviews.llvm.org/D117016