[flang][openacc] Add clause validaty tests for data construct + fix default restriction

Add clause validity tests for the data construct. The default clause can appear only once
and this was not enforce in the ACC.td.

Reviewed By: sameeranjoshi

Differential Revision: https://reviews.llvm.org/D91888

flang/test/Semantics/acc-clause-validity.f90

@@ -131,7 +131,42 @@ program openacc_clause_validity
   !$acc data
   !$acc end data
 
-  !$acc data copyin(i)
+  !$acc data copy(aa) if(.true.)
+  !$acc end data
+
+  !$acc data copy(aa) if(ifCondition)
+  !$acc end data
+
+  !$acc data copy(aa, bb, cc)
+  !$acc end data
+
+  !$acc data copyin(aa) copyin(readonly: bb) copyout(cc)
+  !$acc end data
+
+  !$acc data copyin(readonly: aa, bb) copyout(zero: cc)
+  !$acc end data
+
+  !$acc data create(aa, bb(:,:)) create(zero: cc(:,:))
+  !$acc end data
+
+  !$acc data no_create(aa) present(bb, cc)
+  !$acc end data
+
+  !$acc data deviceptr(aa) attach(bb, cc)
+  !$acc end data
+
+  !$acc data copy(aa, bb) default(none)
+  !$acc end data
+
+  !$acc data copy(aa, bb) default(present)
+  !$acc end data
+
+  !ERROR: At most one DEFAULT clause can appear on the DATA directive
+  !$acc data copy(aa, bb) default(none) default(present)
+  !$acc end data
+
+  !ERROR: At most one IF clause can appear on the DATA directive
+  !$acc data copy(aa) if(.true.) if(ifCondition)
   !$acc end data
 
   !$acc data copyin(i)

llvm/include/llvm/Frontend/OpenACC/ACC.td

@@ -257,7 +257,8 @@ def ACC_Atomic : Directive<"atomic"> {}
 // 2.6.5
 def ACC_Data : Directive<"data"> {
   let allowedOnceClauses = [
-    VersionedClause<ACCC_If>
+    VersionedClause<ACCC_If>,
+    VersionedClause<ACCC_Default>
   ];
   let requiredClauses = [
     VersionedClause<ACCC_Attach>,