feat: Add nv22 skeleton

fvm/src/gas/price_list.rs

@@ -973,7 +973,7 @@ impl PriceList {
 /// Returns gas price list by NetworkVersion for gas consumption.
 pub fn price_list_by_network_version(network_version: NetworkVersion) -> &'static PriceList {
     match network_version {
-        NetworkVersion::V21 => &WATERMELON_PRICES,
+        NetworkVersion::V21 | NetworkVersion::V22 => &WATERMELON_PRICES,
         _ => panic!("network version {nv} not supported", nv = network_version),
     }
 }

fvm/src/machine/default.rs

@@ -58,9 +58,14 @@ where
     /// * `blockstore`: The underlying [blockstore][`Blockstore`] for reading/writing state.
     /// * `externs`: Client-provided ["external"][`Externs`] methods for accessing chain state.
     pub fn new(context: &MachineContext, blockstore: B, externs: E) -> anyhow::Result<Self> {
+        #[cfg(not(feature = "nv22-dev"))]
         const SUPPORTED_VERSIONS: RangeInclusive<NetworkVersion> =
             NetworkVersion::V21..=NetworkVersion::V21;
 
+        #[cfg(feature = "nv22-dev")]
+        const SUPPORTED_VERSIONS: RangeInclusive<NetworkVersion> =
+            NetworkVersion::V21..=NetworkVersion::V22;
+
         debug!(
             "initializing a new machine, epoch={}, base_fee={}, nv={:?}, root={}",
             context.epoch, &context.base_fee, context.network_version, context.initial_state_root

shared/src/version/mod.rs

@@ -57,6 +57,8 @@ impl NetworkVersion {
     pub const V20: Self = Self(20);
     /// Watermelon (builtin-actors v12)
     pub const V21: Self = Self(21);
+    /// TBD builtin-actors v123
+    pub const V22: Self = Self(22);
 
     pub const MAX: Self = Self(u32::MAX);