vm(hako): dispatcher v1 flow scan (opt-in HAKO_V1_DISPATCHER_FLOW), extend extern_provider stubs, parity canary; share block scan used from Mini-VM; keep Core fallback for unsupported ops

lang/src/vm/hakorune-vm/dispatcher_v1.hako

@@ -38,8 +38,71 @@ static box NyVmDispatcherV1Box {
     }
     return 0
   }
+  // Internal scanner with simple flow: const/compare/mir_call/branch/jump/ret (phi→fallback)
+  run_scan_flow(json) {
+    json = "" + json
+    local regs = new MiniMap()
+    local last_cmp_dst = -1
+    local last_cmp_val = 0
+    local bb = 0
+    local steps = 0
+    local max_steps = 200000
+    loop(true) {
+      steps = steps + 1
+      if steps > max_steps { return 0 }
+      local start = JsonV1ReaderBox.block_insts_start(json, bb)
+      if start < 0 { return 0 }
+      local endp = JsonCursorBox.seek_array_end(json, start)
+      if endp <= start { return 0 }
+      local seg = (""+json).substring(start + 1, endp)
+      local scan = 0
+      loop(true) {
+        if scan >= seg.length() { break }
+        local tup = InstructionScannerBox.next_tuple(seg, scan)
+        if tup == "" { break }
+        local c1 = StringOps.index_of_from(tup, ",", 0)
+        local c2 = StringOps.index_of_from(tup, ",", c1+1)
+        if c1 < 0 || c2 < 0 { break }
+        local s = JsonFragBox._str_to_int(tup.substring(0, c1))
+        local e = JsonFragBox._str_to_int(tup.substring(c1+1, c2))
+        local op = tup.substring(c2+1, tup.length())
+        local item = seg.substring(s, e)
+        if op == "const" { OpHandlersBox.handle_const(item, regs) }
+        else if op == "compare" {
+          OpHandlersBox.handle_compare(item, regs)
+          local dst = JsonFragBox.get_int(item, "dst")
+          if dst != null {
+            last_cmp_dst = dst
+            local sv = regs.getField(""+dst); if sv != null { last_cmp_val = JsonFragBox._str_to_int(""+sv) } else { last_cmp_val = 0 }
+          }
+        }
+        else if op == "mir_call" { MirCallV1HandlerBox.handle(item, regs) }
+        else if op == "branch" {
+          local c = JsonFragBox.get_int(item, "cond")
+          local t = JsonFragBox.get_int(item, "then")
+          local f = JsonFragBox.get_int(item, "else")
+          if c != null && t != null && f != null {
+            local cv = 0
+            if c == last_cmp_dst { cv = last_cmp_val } else { local sv = regs.getField(""+c); if sv != null { cv = JsonFragBox._str_to_int(""+sv) } }
+            bb = (cv != 0) ? t : f
+            break
+          } else { return MirVmMin.run_min(json) }
+        }
+        else if op == "jump" {
+          local tgt = JsonFragBox.get_int(item, "target"); if tgt == null { return MirVmMin.run_min(json) }
+          bb = tgt; break
+        }
+        else if op == "phi" {
+          return MirVmMin.run_min(json)
+        }
+        else if op == "ret" { return MirVmMin._handle_ret_op(item, regs, last_cmp_dst, last_cmp_val, 0) }
+        scan = e
+      }
+    }
+  }
   // Main entry: Choose internal scanner when enabled; otherwise delegate to Mini‑VM
   run(json) {
+    if env.get("HAKO_V1_DISPATCHER_FLOW") == "1" { return me.run_scan_flow(json) }
     if env.get("HAKO_V1_DISPATCHER_INTERNAL") == "1" { return me.run_scan(json) }
     return MirVmMin.run_min(json)
   }

lang/src/vm/hakorune-vm/extern_provider.hako

@@ -17,6 +17,14 @@ static box HakoruneExternProviderBox {
       print("" + args)
       return 0
     }
+    if name == "env.mirbuilder.emit" {
+      // Stub only (20.38でC‑ABI接続): return empty string
+      return ""
+    }
+    if name == "env.codegen.emit_object" {
+      // Stub only: return empty string (path placeholder)
+      return ""
+    }
     // Unknown: return null for now (caller decides Fail‑Fast)
     return null
   }