[MLIR][OpenMP] NFC: Address tablegen warnings (#98485)

After the addition of the `-verify-openmp-ops` tablegen pseudo-backend
to report suspected issues with the definition of an operation, some
warnings were triggered in the current implementation of OpenMPOps.td.

These are related to known limitations for which TODO messages exist
within these operation's definitions. This patch explicitly inhibits the
inheritance of the `assemblyFormat` property of all clauses added to the
`omp.parallel` and `omp.wsloop` operations to avoid these warnings. This
should help identifying actual issues that may arise later as the
dialect continues to be developed.

mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td

@@ -133,8 +133,12 @@ def ParallelOp : OpenMP_Op<"parallel", traits = [
     RecursiveMemoryEffects
   ], clauses = [
     // TODO: Sort clauses alphabetically.
-    OpenMP_IfClause, OpenMP_NumThreadsClause, OpenMP_AllocateClause,
-    OpenMP_ReductionClause, OpenMP_ProcBindClause, OpenMP_PrivateClause
+    OpenMP_IfClauseSkip<assemblyFormat = true>,
+    OpenMP_NumThreadsClauseSkip<assemblyFormat = true>,
+    OpenMP_AllocateClauseSkip<assemblyFormat = true>,
+    OpenMP_ReductionClauseSkip<assemblyFormat = true>,
+    OpenMP_ProcBindClauseSkip<assemblyFormat = true>,
+    OpenMP_PrivateClauseSkip<assemblyFormat = true>
   ], singleRegion = true> {
   let summary = "parallel construct";
   let description = [{
@@ -154,7 +158,8 @@ def ParallelOp : OpenMP_Op<"parallel", traits = [
 
   // TODO: Use default assembly format inherited from OpenMP_Op once printing
   // and parsing of the parallel region is not intermingled with printing and
-  // parsing of reduction and private clauses.
+  // parsing of reduction and private clauses. `assemblyFormat` should also be
+  // no longer skipped for clauses added to this operation at that time.
   let assemblyFormat = [{
     oilist(
           `if` `(` $if_expr `)`
@@ -363,8 +368,12 @@ def WsloopOp : OpenMP_Op<"wsloop", traits = [
   ], clauses = [
     // TODO: Complete clause list (allocate, private).
     // TODO: Sort clauses alphabetically.
-    OpenMP_LinearClause, OpenMP_ReductionClause, OpenMP_ScheduleClause,
-    OpenMP_NowaitClause, OpenMP_OrderedClause, OpenMP_OrderClause
+    OpenMP_LinearClauseSkip<assemblyFormat = true>,
+    OpenMP_ReductionClauseSkip<assemblyFormat = true>,
+    OpenMP_ScheduleClauseSkip<assemblyFormat = true>,
+    OpenMP_NowaitClauseSkip<assemblyFormat = true>,
+    OpenMP_OrderedClauseSkip<assemblyFormat = true>,
+    OpenMP_OrderClauseSkip<assemblyFormat = true>
   ], singleRegion = true> {
   let summary = "worksharing-loop construct";
   let description = [{
@@ -398,7 +407,8 @@ def WsloopOp : OpenMP_Op<"wsloop", traits = [
 
   // TODO: Use default assembly format inherited from OpenMP_Op once printing
   // and parsing of the workshare loop region is not intermingled with printing
-  // and parsing of reduction clauses.
+  // and parsing of reduction clauses. `assemblyFormat` should also be no longer
+  // skipped for clauses added to this operation at that time.
   let assemblyFormat = [{
     oilist(`linear` `(`
               custom<LinearClause>($linear_vars, type($linear_vars),