Contracts: Stabilize APIs (#3384)

Remove `#[unstable]` on `call_v2`, `instantiate_v2`,
`lock_delegate_dependency` and `unlock_delegate_dependency`.
See ink! integrations: 
- call_v2: https://github.com/paritytech/ink/pull/2077
- instantiate_v2: <TODO>
- lock/unlock dependency: https://github.com/paritytech/ink/pull/2076

substrate/frame/contracts/uapi/src/host.rs

@@ -93,7 +93,7 @@ pub trait HostFn {
 	/// - `output`: A reference to the output data buffer to write the address.
 	fn address(output: &mut &mut [u8]);
 
-	/// Adds a new delegate dependency to the contract.
+	/// Lock a new delegate dependency to the contract.
 	///
 	/// Traps if the maximum number of delegate_dependencies is reached or if
 	/// the delegate dependency already exists.
@@ -102,10 +102,7 @@ pub trait HostFn {
 	///
 	/// - `code_hash`: The code hash of the dependency. Should be decodable as an `T::Hash`. Traps
 	///   otherwise.
-	#[deprecated(
-		note = "Unstable function. Behaviour can change without further notice. Use only for testing."
-	)]
-	fn add_delegate_dependency(code_hash: &[u8]);
+	fn lock_delegate_dependency(code_hash: &[u8]);
 
 	/// Stores the *free* balance of the current account into the supplied buffer.
 	///
@@ -142,6 +139,7 @@ pub trait HostFn {
 	///
 	/// Equivalent to the newer [`Self::call_v2`] version but works with
 	/// *ref_time* Weight only
+	#[deprecated(note = "Deprecated, use newer version instead")]
 	fn call_v1(
 		flags: CallFlags,
 		callee: &[u8],
@@ -178,9 +176,6 @@ pub trait HostFn {
 	/// - [CalleeTrapped][`crate::ReturnErrorCode::CalleeTrapped]
 	/// - [TransferFailed][`crate::ReturnErrorCode::TransferFailed]
 	/// - [NotCallable][`crate::ReturnErrorCode::NotCallable]
-	#[deprecated(
-		note = "Unstable function. Behaviour can change without further notice. Use only for testing."
-	)]
 	fn call_v2(
 		flags: CallFlags,
 		callee: &[u8],
@@ -480,6 +475,7 @@ pub trait HostFn {
 	///
 	/// Equivalent to the newer [`Self::instantiate_v2`] version but works
 	/// with *ref_time* Weight only.
+	#[deprecated(note = "Deprecated, use newer version instead")]
 	fn instantiate_v1(
 		code_hash: &[u8],
 		gas: u64,
@@ -524,9 +520,6 @@ pub trait HostFn {
 	/// - [CalleeTrapped][`crate::ReturnErrorCode::CalleeTrapped]
 	/// - [TransferFailed][`crate::ReturnErrorCode::TransferFailed]
 	/// - [CodeNotFound][`crate::ReturnErrorCode::CodeNotFound]
-	#[deprecated(
-		note = "Unstable function. Behaviour can change without further notice. Use only for testing."
-	)]
 	fn instantiate_v2(
 		code_hash: &[u8],
 		ref_time_limit: u64,
@@ -602,10 +595,7 @@ pub trait HostFn {
 	///
 	/// - `code_hash`: The code hash of the dependency. Should be decodable as an `T::Hash`. Traps
 	///   otherwise.
-	#[deprecated(
-		note = "Unstable function. Behaviour can change without further notice. Use only for testing."
-	)]
-	fn remove_delegate_dependency(code_hash: &[u8]);
+	fn unlock_delegate_dependency(code_hash: &[u8]);
 
 	/// Cease contract execution and save a data buffer as a result of the execution.
 	///

substrate/frame/contracts/uapi/src/host/riscv32.rs

@@ -281,11 +281,11 @@ impl HostFn for HostFnImpl {
 		todo!()
 	}
 
-	fn add_delegate_dependency(code_hash: &[u8]) {
+	fn lock_delegate_dependency(code_hash: &[u8]) {
 		todo!()
 	}
 
-	fn remove_delegate_dependency(code_hash: &[u8]) {
+	fn unlock_delegate_dependency(code_hash: &[u8]) {
 		todo!()
 	}
 

substrate/frame/contracts/uapi/src/host/wasm32.rs

@@ -23,7 +23,7 @@ mod sys {
 	extern "C" {
 		pub fn account_reentrance_count(account_ptr: *const u8) -> u32;
 
-		pub fn add_delegate_dependency(code_hash_ptr: *const u8);
+		pub fn lock_delegate_dependency(code_hash_ptr: *const u8);
 
 		pub fn address(output_ptr: *mut u8, output_len_ptr: *mut u32);
 
@@ -125,7 +125,7 @@ mod sys {
 
 		pub fn reentrance_count() -> u32;
 
-		pub fn remove_delegate_dependency(code_hash_ptr: *const u8);
+		pub fn unlock_delegate_dependency(code_hash_ptr: *const u8);
 
 		pub fn seal_return(flags: u32, data_ptr: *const u8, data_len: u32) -> !;
 
@@ -803,12 +803,12 @@ impl HostFn for HostFnImpl {
 		unsafe { sys::account_reentrance_count(account.as_ptr()) }
 	}
 
-	fn add_delegate_dependency(code_hash: &[u8]) {
-		unsafe { sys::add_delegate_dependency(code_hash.as_ptr()) }
+	fn lock_delegate_dependency(code_hash: &[u8]) {
+		unsafe { sys::lock_delegate_dependency(code_hash.as_ptr()) }
 	}
 
-	fn remove_delegate_dependency(code_hash: &[u8]) {
-		unsafe { sys::remove_delegate_dependency(code_hash.as_ptr()) }
+	fn unlock_delegate_dependency(code_hash: &[u8]) {
+		unsafe { sys::unlock_delegate_dependency(code_hash.as_ptr()) }
 	}
 
 	fn instantiation_nonce() -> u64 {