[flang][OpenMP][OpenACC] Fix exit of a region

The stop statement is allowed in OpenMP/OpenACC block region.

Reviewed By: kiranchandramohan, shraiysh

Differential Revision: https://reviews.llvm.org/D126471

flang/lib/Semantics/check-directive-structure.h

@@ -58,7 +58,6 @@ public:
       CheckConstructNameBranching("EXIT");
     }
   }
-  void Post(const parser::StopStmt &) { EmitBranchOutError("STOP"); }
   void Post(const parser::CycleStmt &cycleStmt) {
     if (const auto &cycleName{cycleStmt.v}) {
       CheckConstructNameBranching("CYCLE", cycleName.value());

flang/test/Semantics/OpenACC/acc-branch.f90

@@ -93,8 +93,7 @@ program openacc_clause_validity
   do i = 1, N
     a(i) = 3.14
     if(i == N-1) THEN
-      !ERROR: STOP statement is not allowed in a PARALLEL construct
-      stop 999
+      stop 999 ! no error
     end if
   end do
   !$acc end parallel
@@ -120,8 +119,7 @@ program openacc_clause_validity
   do i = 1, N
     a(i) = 3.14
     if(i == N-1) THEN
-      !ERROR: STOP statement is not allowed in a KERNELS construct
-      stop 999
+      stop 999 ! no error
     end if
   end do
   !$acc end kernels
@@ -163,8 +161,7 @@ program openacc_clause_validity
   do i = 1, N
     a(i) = 3.14
     if(i == N-1) THEN
-      !ERROR: STOP statement is not allowed in a SERIAL construct
-      stop 999
+      stop 999 ! no error
     end if
   end do
   !$acc end serial

flang/test/Semantics/omp-parallel02.f90

@@ -15,7 +15,6 @@ program omp_parallel
     do j = 1, 10
       print *, "Hello"
       !CHECK: In the enclosing PARALLEL directive branched into
-      !CHECK: STOP statement is not allowed in a PARALLEL construct
       10 stop
     end do
   end do

flang/test/Semantics/omp-task01.f90

@@ -17,7 +17,6 @@ recursive subroutine traverse ( P )
     !$omp task
     call traverse(P%left)
     !CHECK: In the enclosing TASK directive branched into
-    !CHECK: STOP statement is not allowed in a TASK construct
     10 stop
     !$omp end task
   endif