[flang][OpenMP] Add lowering test: lastprivate on DO is scoped to wsloop (guards #157035)

Author: KrxGu

flang/test/Lower/OpenMP/lastprivate-alloc-scope.f90

@@ -0,0 +1,22 @@
+! RUN: %flang_fc1 -fopenmp -emit-hlfir %s -o - | FileCheck %s
+
+program p
+  type y3; integer, allocatable :: x; end type
+  type(y3) :: v
+  integer :: s, n, i
+  s = 1; n = 10
+  allocate(v%x); v%x = 0
+!$omp parallel
+  if (.not. allocated(v%x)) print *, '101', allocated(v%x)
+!$omp do schedule(dynamic) lastprivate(v)
+  do i = s, n
+    v%x = i
+  end do
+!$omp end do
+!$omp end parallel
+end program
+
+! CHECK:      omp.parallel {
+! CHECK-NOT:  private(
+! CHECK:      omp.wsloop
+! CHECK-SAME: private(