Switch to pooling copy-on-write instantiation strategy for WASM (#11232)

* Switch to pooling copy-on-write instantiation strategy for WASM

* Fix benchmark compilation

* Fix `cargo fmt`

* Fix compilation of another benchmark I've missed

* Cleanups according to review comments

* Move `max_memory_size` to `Semantics`

* Set `memory_guaranteed_dense_image_size` to `max_memory_size`

* Rename `wasm_instantiation_strategy` to `wasmtime_instantiation_strategy`

* Update the doc-comments regarding the instantiation strategy

* Extend the integration tests to test every instantiation strategy

* Don't drop the temporary directory until the runtime is dropped in benchmarks

* Don't drop the temporary directory until the runtime is dropped in tests

substrate/bin/node/executor/benches/bench.rs

@@ -25,6 +25,8 @@ use node_runtime::{
 	UncheckedExtrinsic,
 };
 use node_testing::keyring::*;
+#[cfg(feature = "wasmtime")]
+use sc_executor::WasmtimeInstantiationStrategy;
 use sc_executor::{Externalities, NativeElseWasmExecutor, RuntimeVersionOf, WasmExecutionMethod};
 use sp_core::{
 	storage::well_known_keys,
@@ -183,7 +185,9 @@ fn bench_execute_block(c: &mut Criterion) {
 		ExecutionMethod::Native,
 		ExecutionMethod::Wasm(WasmExecutionMethod::Interpreted),
 		#[cfg(feature = "wasmtime")]
-		ExecutionMethod::Wasm(WasmExecutionMethod::Compiled),
+		ExecutionMethod::Wasm(WasmExecutionMethod::Compiled {
+			instantiation_strategy: WasmtimeInstantiationStrategy::PoolingCopyOnWrite,
+		}),
 	];
 
 	for strategy in execution_methods {