Re-add deprecated --execution arg on benchmark pallet (#14567)

* Add DeferGuard::new

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Re-add deprecated 'execution' arg to benchmark pallet cmd.

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Extend tests

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Remove from tests

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

substrate/utils/frame/benchmarking-cli/src/pallet/command.rs

@@ -147,6 +147,16 @@ impl PalletCmd {
 		<<<BB as BlockT>::Header as HeaderT>::Number as std::str::FromStr>::Err: std::fmt::Debug,
 		ExtraHostFunctions: sp_wasm_interface::HostFunctions,
 	{
+		let _d = self.execution.as_ref().map(|exec| {
+			// We print the warning at the end, since there is often A LOT of output.
+			sp_core::defer::DeferGuard::new(move || {
+				log::warn!(
+					target: LOG_TARGET,
+					"⚠️  Argument `--execution` is deprecated. Its value of `{exec}` has on effect.",
+				)
+			})
+		});
+
 		if let Some(output_path) = &self.output {
 			if !output_path.is_dir() && output_path.file_name().is_none() {
 				return Err("Output file or path is invalid!".into())

substrate/utils/frame/benchmarking-cli/src/pallet/mod.rs

@@ -150,6 +150,10 @@ pub struct PalletCmd {
 	)]
 	pub wasmtime_instantiation_strategy: WasmtimeInstantiationStrategy,
 
+	/// DEPRECATED: This argument has no effect.
+	#[arg(long = "execution")]
+	pub execution: Option<String>,
+
 	/// Limit the memory the database cache can use.
 	#[arg(long = "db-cache", value_name = "MiB", default_value_t = 1024)]
 	pub database_cache_size: u32,