fix(mir): PHI検証panic修正 - update_cfg()を検証前に呼び出し

A案実装: debug_verify_phi_inputs呼び出し前にCFG predecessorを更新

修正箇所（7箇所）:
- src/mir/builder/phi.rs:50, 73, 132, 143
- src/mir/builder/ops.rs:273, 328, 351

根本原因:
- Branch/Jump命令でsuccessorは即座に更新
- predecessorはupdate_cfg()で遅延再構築
- PHI検証が先に実行されてpredecessor未更新でpanic

解決策:
- 各debug_verify_phi_inputs呼び出し前に
  if let Some(func) = self.current_function.as_mut() {
      func.update_cfg();
  }
  を挿入してCFGを同期

影響: if/else文、論理演算子(&&/||)のPHI生成が正常動作

lang/src/compiler/parser/expr/parser_expr_box.hako

@@ -13,13 +13,13 @@ static box ParserExprBox {
     local at = pair.lastIndexOf("@")
     local json = pair.substring(0, at)
     local pos = i
-    if at >= 0 { pos = ctx.to_int(pair.substring(at+1, pair.size())) }
+    if at >= 0 { pos = ctx.to_int(pair.substring(at+1, pair.length())) }
     ctx.gpos_set(pos)
     return json
   }
 
   parse_string2(src, i, ctx) {
-    local n = src.size()
+    local n = src.length()
     local j = i + 1
     local out = ""
     local guard = 0
@@ -57,7 +57,7 @@ static box ParserExprBox {
 
   parse_factor2(src, i, ctx) {
     local j = ctx.skip_ws(src, i)
-    if j >= src.size() {
+    if j >= src.length() {
       ctx.gpos_set(j)
       return "{\"type\":\"Int\",\"value\":0}"
     }
@@ -116,13 +116,13 @@ static box ParserExprBox {
       local idp = ctx.read_ident2(src, p)
       local at = idp.lastIndexOf("@")
       local cls = idp.substring(0, at)
-      local k = ctx.to_int(idp.substring(at+1, idp.size()))
+      local k = ctx.to_int(idp.substring(at+1, idp.length()))
       k = ctx.skip_ws(src, k)
       if src.substring(k, k+1) == "(" { k = k + 1 }
       local args_and_pos = me.parse_args2(src, k, ctx)
       local at2 = args_and_pos.lastIndexOf("@")
       local args_json = args_and_pos.substring(0, at2)
-      k = ctx.to_int(args_and_pos.substring(at2+1, args_and_pos.size()))
+      k = ctx.to_int(args_and_pos.substring(at2+1, args_and_pos.length()))
       k = ctx.skip_ws(src, k)
       if src.substring(k, k+1) == ")" { k = k + 1 }
       ctx.gpos_set(k)
@@ -134,7 +134,7 @@ static box ParserExprBox {
       local idp = ctx.read_ident2(src, j)
       local at = idp.lastIndexOf("@")
       local name = idp.substring(0, at)
-      local k = ctx.to_int(idp.substring(at+1, idp.size()))
+      local k = ctx.to_int(idp.substring(at+1, idp.length()))
       local node = "{\"type\":\"Var\",\"name\":\"" + name + "\"}"
       local cont2 = 1
 
@@ -147,7 +147,7 @@ static box ParserExprBox {
           local args_and_pos = me.parse_args2(src, k, ctx)
           local at2 = args_and_pos.lastIndexOf("@")
           local args_json = args_and_pos.substring(0, at2)
-          k = ctx.to_int(args_and_pos.substring(at2+1, args_and_pos.size()))
+          k = ctx.to_int(args_and_pos.substring(at2+1, args_and_pos.length()))
           k = ctx.skip_ws(src, k)
           if src.substring(k, k+1) == ")" { k = k + 1 }
           node = "{\"type\":\"Call\",\"name\":\"" + name + "\",\"args\":" + args_json + "}"
@@ -158,13 +158,13 @@ static box ParserExprBox {
             local midp = ctx.read_ident2(src, k)
             local at3 = midp.lastIndexOf("@")
             local mname = midp.substring(0, at3)
-            k = ctx.to_int(midp.substring(at3+1, midp.size()))
+            k = ctx.to_int(midp.substring(at3+1, midp.length()))
             k = ctx.skip_ws(src, k)
             if src.substring(k, k+1) == "(" { k = k + 1 }
             local args2 = me.parse_args2(src, k, ctx)
             local at4 = args2.lastIndexOf("@")
             local args_json2 = args2.substring(0, at4)
-            k = ctx.to_int(args2.substring(at4+1, args2.size()))
+            k = ctx.to_int(args2.substring(at4+1, args2.length()))
             k = ctx.skip_ws(src, k)
             if src.substring(k, k+1) == ")" { k = k + 1 }
             node = "{\"type\":\"Method\",\"recv\":" + node + ",\"method\":\"" + mname + "\",\"args\":" + args_json2 + "}"
@@ -201,7 +201,7 @@ static box ParserExprBox {
 
     loop(cont == 1) {
       j = ctx.skip_ws(src, j)
-      if j >= src.size() {
+      if j >= src.length() {
         cont = 0
       } else {
         local op = src.substring(j, j+1)
@@ -226,7 +226,7 @@ static box ParserExprBox {
 
     loop(cont == 1) {
       j = ctx.skip_ws(src, j)
-      if j >= src.size() {
+      if j >= src.length() {
         cont = 0
       } else {
         local op = src.substring(j, j+1)
@@ -301,7 +301,7 @@ static box ParserExprBox {
       j = ctx.skip_ws(src, j)
       local else_expr = me.parse_expr2(src, j, ctx)
       j = ctx.gpos_get()
-      if else_expr.size() == 0 { else_expr = "{\"type\":\"Int\",\"value\":0}" }
+      if else_expr.length() == 0 { else_expr = "{\"type\":\"Int\",\"value\":0}" }
       ctx.gpos_set(j)
       return "{\"type\":\"Ternary\",\"cond\":" + lhs + ",\"then\":" + then_expr + ",\"else\":" + else_expr + "}"
     }
@@ -312,7 +312,7 @@ static box ParserExprBox {
 
   parse_args2(src, i, ctx) {
     local j = ctx.skip_ws(src, i)
-    local n = src.size()
+    local n = src.length()
     local out = "["
     j = ctx.skip_ws(src, j)
 

lang/src/compiler/parser/expr/parser_literal_box.hako

@@ -6,7 +6,7 @@
 static box ParserLiteralBox {
   // Map literal: {"k": v, ...} (string keys only) → Call{name:"map.of", args:[Str(k1), v1, Str(k2), v2, ...]}
   parse_map(src, i, ctx) {
-    local n = src.size()
+    local n = src.length()
     local j = i + 1  // skip opening '{'
     local out = "["
     local first = 1
@@ -68,7 +68,7 @@ static box ParserLiteralBox {
 
   // Array literal: [e1, e2, ...] → Call{name:"array.of", args:[...]}
   parse_array(src, i, ctx) {
-    local n = src.size()
+    local n = src.length()
     local j = i + 1  // skip opening '['
     local out = "["
     local first = 1

lang/src/compiler/parser/expr/parser_peek_box.hako

@@ -7,7 +7,7 @@ static box ParserPeekBox {
   parse(src, i, ctx) {
     // ctx is ParserBox for delegation
     local j = i
-    local n = src.size()
+    local n = src.length()
 
     // Parse scrutinee expression
     local scr = ctx.parse_expr2(src, j)