Use feature gate to set effective slot of loaded programs (#30950)

program-runtime/src/loaded_programs.rs

@@ -132,6 +132,7 @@ impl LoadedProgram {
         loader_key: &Pubkey,
         loader: Arc<BuiltInProgram<InvokeContext<'static>>>,
         deployment_slot: Slot,
+        effective_slot: Slot,
         elf_bytes: &[u8],
         account_size: usize,
         use_jit: bool,
@@ -176,7 +177,7 @@ impl LoadedProgram {
         Ok(Self {
             deployment_slot,
             account_size,
-            effective_slot: deployment_slot.saturating_add(1),
+            effective_slot,
             usage_counter: AtomicU64::new(0),
             program,
         })

programs/bpf_loader/src/lib.rs

@@ -119,10 +119,17 @@ pub fn load_program_from_bytes(
     register_syscalls_time.stop();
     load_program_metrics.register_syscalls_us = register_syscalls_time.as_us();
 
+    let effective_slot = if feature_set.is_active(&delay_visibility_of_program_deployment::id()) {
+        deployment_slot.saturating_add(1)
+    } else {
+        deployment_slot
+    };
+
     let loaded_program = LoadedProgram::new(
         loader_key,
         loader,
         deployment_slot,
+        effective_slot,
         programdata,
         account_size,
         use_jit,

programs/loader-v3/src/lib.rs

@@ -114,6 +114,7 @@ pub fn load_program_from_account(
         &loader_v3::id(),
         Arc::new(loader),
         state.slot,
+        state.slot.saturating_add(1),
         programdata,
         program.get_data().len(),
         use_jit,