[mlir][openacc] Add ReturnLike trait to acc.yield operation

[clementval]

Summary

Just add the trait as acc.yield is a return like op.

mlir/include/mlir/Dialect/OpenACC/OpenACC.h

 
 #include "mlir/IR/BuiltinTypes.h"
 #include "mlir/IR/Dialect.h"
 #include "mlir/IR/OpDefinition.h"
 
 #include "mlir/Dialect/OpenACC/OpenACCOpsDialect.h.inc"
 #include "mlir/Dialect/OpenACC/OpenACCOpsEnums.h.inc"
 #include "mlir/Dialect/OpenACC/OpenACCTypeInterfaces.h.inc"
+#include "mlir/Interfaces/ControlFlowInterfaces.h"
 #include "mlir/Interfaces/SideEffectInterfaces.h"
 
 #define GET_TYPEDEF_CLASSES
 #include "mlir/Dialect/OpenACC/OpenACCOpsTypes.h.inc"
 
 #define GET_ATTRDEF_CLASSES
 #include "mlir/Dialect/OpenACC/OpenACCOpsAttributes.h.inc"
 

mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td

 //===- OpenACCOps.td - OpenACC operation definitions -------*- tablegen -*-===//
 //
 // Part of the MLIR Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // =============================================================================
 //
 // Defines MLIR OpenACC operations.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef OPENACC_OPS
 #define OPENACC_OPS
 
+include "mlir/Interfaces/ControlFlowInterfaces.td"
 include "mlir/Interfaces/SideEffectInterfaces.td"
 include "mlir/IR/BuiltinTypes.td"
 include "mlir/IR/EnumAttr.td"
 include "mlir/IR/OpBase.td"
 include "mlir/Dialect/OpenACC/OpenACCBase.td"
 include "mlir/Dialect/OpenACC/OpenACCOpsTypes.td"
 include "mlir/Dialect/OpenACC/OpenACCTypeInterfaces.td"
 
let assemblyFormat = [{
     ( `(` type($results)^ `)` )?
     attr-dict-with-keyword
   }];
 
   let hasVerifier = 1;
 }
 
 // Yield operation for the acc.loop and acc.parallel operations.
-def OpenACC_YieldOp : OpenACC_Op<"yield", [Terminator,
+def OpenACC_YieldOp : OpenACC_Op<"yield", [ReturnLike, Terminator,
     ParentOneOf<["ParallelOp, LoopOp, SerialOp"]>]> {
   let summary = "Acc yield and termination operation";
 
   let description = [{
     `acc.yield` is a special terminator operation for block inside regions in
     acc ops (parallel and loop). It returns values to the immediately enclosing
     acc op.
   }];