OpenMP/C++: Avoid ICE for BIND_EXPR with empty BIND_EXPR_BLOCK [PR120413]

	PR c++/120413

gcc/cp/ChangeLog:

	* semantics.cc (finish_omp_target_clauses_r): Handle
	BIND_EXPR with empty BIND_EXPR_BLOCK.

gcc/testsuite/ChangeLog:

	* g++.dg/gomp/target-4.C: New test.

Author: tob2

gcc/cp/semantics.cc

@@ -10565,10 +10565,10 @@ finish_omp_target_clauses_r (tree *tp, int *walk_subtrees, void *ptr)
 
   if (TREE_CODE (t) == BIND_EXPR)
     {
-      tree block = BIND_EXPR_BLOCK (t);
-      for (tree var = BLOCK_VARS (block); var; var = DECL_CHAIN (var))
-	if (!data->local_decls.contains (var))
-	  data->local_decls.add (var);
+      if (tree block = BIND_EXPR_BLOCK (t))
+	for (tree var = BLOCK_VARS (block); var; var = DECL_CHAIN (var))
+	  if (!data->local_decls.contains (var))
+	    data->local_decls.add (var);
       return NULL_TREE;
     }
 

gcc/testsuite/g++.dg/gomp/target-4.C

@@ -0,0 +1,22 @@
+// { dg-do compile { target c++11 } }
+// PR c++/120413
+
+struct S
+{
+  S() {}
+  ~S() {}
+};
+
+struct array
+{
+  S _arr[1];
+};
+
+int main()
+{
+#pragma omp target
+  {
+    array arr{};
+  }
+  return 0;
+}