[flang][fir] Add missing HasParent in fir_DTEntryOp

Differential Revision: https://reviews.llvm.org/D113674

Author: banach-space

flang/include/flang/Optimizer/Dialect/FIROps.td

@@ -2870,7 +2870,7 @@ def fir_DispatchTableOp : fir_Op<"dispatch_table",
   }];
 }
 
-def fir_DTEntryOp : fir_Op<"dt_entry", []> {
+def fir_DTEntryOp : fir_Op<"dt_entry", [HasParent<"DispatchTableOp">]> {
   let summary = "map entry in a dispatch table";
 
   let description = [{

flang/test/Fir/convert-to-llvm-invalid.fir

@@ -93,3 +93,10 @@ func @gentypedesc() {
   %0 = fir.gentypedesc !fir.type<derived3>
   return
 }
+
+// -----
+
+// Verify that `fir.dt_entry` requires a parent op
+
+// expected-error@+1{{'fir.dt_entry' op expects parent op 'fir.dispatch_table'}}
+fir.dt_entry "method", @method_impl