[Flang][OpenMP] Prevent re-composition of composite constructs (#102613)

After decomposition of OpenMP compound constructs and assignment of
applicable clauses to each leaf construct, composite constructs are then
combined again into a single element in the construct queue. This helped
later lowering stages easily identify composite constructs.

However, as a result of the re-composition stage, the same list of
clauses is used to produce all MLIR operations corresponding to each
leaf of the original composite construct. This undoes existing logic
introducing implicit clauses and deciding to which leaf construct(s)
each clause applies.

This patch removes construct re-composition logic and updates Flang
lowering to be able to identify composite constructs from a list of leaf
constructs. As a result, the right set of clauses is produced for each
operation representing a leaf of a composite construct.

PR stack:
- #102612
- #102613

0 files changed, 0 insertions, 0 deletions