[OpenMP] Add OutlineableOpenMPOpInterface trait to TargetOp

This patch adds the OutlineableOpenMPOpInterface to omp.target. This prevents other operations inside the target region such as WSLoop from hoisting new allocas outside the region.

Author: TIFitis

mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td

@@ -1375,7 +1375,7 @@ def Target_ExitDataOp: OpenMP_Op<"target_exit_data",
 // 2.14.5 target construct
 //===----------------------------------------------------------------------===//
 
-def TargetOp : OpenMP_Op<"target",[AttrSizedOperandSegments]> {
+def TargetOp : OpenMP_Op<"target",[OutlineableOpenMPOpInterface, AttrSizedOperandSegments]> {
   let summary = "target construct";
   let description = [{
     The target construct includes a region of code which is to be executed