📦 Hotfix 4: Static Method Receiver ValueId Reservation

**根本原因**: Static method (e.g., `collect_entries/1`) は暗黙の 'me' receiver を持つが、signature.params に含まれていない

**問題の構造**:
```
static box Stage1UsingResolverFull {
    collect_entries(src_unused) {  // signature: /1 (1 param)
        me._find_from(...)          // 'me' を使用！
    }
}
```

- Signature: params.len() = 1 (src_unused のみ)
- 実際の ValueIds: 2つ必要 (%0 = receiver/me, %1 = src_unused)

**修正内容**:
src/mir/function.rs - MirFunction::new() で static method 判定追加:

1. **判定ロジック**:
   - Function name に "." が含まれる → box method or static method
   - params[0] が Box type でない → static method (implicit receiver)
   - → +1 ValueId for receiver

2. **予約計算**:
   ```rust
   let receiver_count = if has_implicit_receiver { 1 } else { 0 };
   let total_value_ids = param_count + receiver_count;
   let initial_counter = total_value_ids.max(1);
   ```

**Test Result**:
```
[MirFunction::new] fn='Stage1UsingResolverFull.collect_entries/1'
  params=1, receiver=1, total=2, initial_counter=2  ✅

[MirFunction::new] fn='Stage1UsingResolverFull._find_from/3'
  params=3, receiver=1, total=4, initial_counter=4  ✅
```

**進捗**:
- ✅ Hotfix 1: Parameter ValueId reservation
- ✅ Hotfix 2: Exit PHI validation
- ✅ Hotfix 3: NewBox ValueId fix
- ✅ Hotfix 4: Static method receiver reservation
- ⏸️ Remaining: bb57 %0 undefined error (別の問題、次セッションで調査)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/mir/function.rs

@@ -77,15 +77,36 @@ impl MirFunction {
         let mut blocks = HashMap::new();
         blocks.insert(entry_block, BasicBlock::new(entry_block));
 
-        // 📦 Hotfix 1: Reserve ValueIds for function parameters at creation time
+        // 📦 Hotfix 1 + 4: Reserve ValueIds for function parameters at creation time
         // Parameter ValueIds are %0, %1, ..., %N-1 where N = signature.params.len()
-        // next_value_id must start at N to avoid overwriting parameters
+        //
+        // 📦 Hotfix 4: Static method receiver reservation
+        // Static methods (e.g., Stage1UsingResolverFull.collect_entries/1) have implicit 'me' receiver
+        // that's not included in signature.params but needs ValueId reservation.
+        //
+        // Detection: If function name contains "." (box method or static method) AND
+        // params[0] is NOT a Box type → static method → needs +1 for receiver
         let param_count = signature.params.len() as u32;
-        let initial_counter = param_count.max(1);  // At least 1 to reserve ValueId(0) as sentinel
+        let has_implicit_receiver = if signature.name.contains('.') {
+            // Box method or static method
+            if signature.params.is_empty() {
+                // No params → static method with only receiver
+                true
+            } else {
+                // Check if first param is Box type (instance method) or not (static method)
+                !matches!(signature.params[0], MirType::Box(_))
+            }
+        } else {
+            false
+        };
+
+        let receiver_count = if has_implicit_receiver { 1 } else { 0 };
+        let total_value_ids = param_count + receiver_count;
+        let initial_counter = total_value_ids.max(1);  // At least 1 to reserve ValueId(0) as sentinel
 
         if std::env::var("NYASH_LOOPFORM_DEBUG").is_ok() {
-            eprintln!("[MirFunction::new] fn='{}' params={}, initial_counter={}",
+            eprintln!("[MirFunction::new] fn='{}' params={}, receiver={}, total={}, initial_counter={}",
-                     signature.name, param_count, initial_counter);
+                     signature.name, param_count, receiver_count, total_value_ids, initial_counter);
         }
 
         Self {