Add support for OpenMP is_device_ptr clause for target directives. [MLIR][OpenMP] Add OpenMPToLLVMIRTranslation support for is_device_ptr #169367 This PR adds support for the OpenMP is_device_ptr clause in the MLIR to LLVM IR translation for target regions. The is_device_ptr clause allows device pointers (allocated via OpenMP runtime APIs) to be used directly in target regions without implicit mapping.