feat(tpv): 语言内协程 M1-M7 移植——async/await 状态机 + 异常传播 + 帧池

- M1: async def -> 帧结构体 + create_/resume_ 状态机 + coro.coro_run 内联
- M2: async 参数、嵌套 await 提升 __await_N、If/While 内 await
- M3: For 内 await（range->While）、coro_sleep 轮询挂起、coro_destroy 回池
- M4: raise 存码、await 子帧异常传播、coro_exception、coro_gather
- M5/M6: try/except 链式匹配 + as e 绑定 + 异常类型码
- M7: try/finally、异常消息 msg 槽、自定义异常类、帧池复用

Test/App/async_test.vp

@@ -0,0 +1,58 @@
+import t, c
+from stdint import *
+import stdio
+import coro
+
+
+# TPV-M3~M7 协程综合测试：
+#   M3: For 内 await（range→While）、coro_sleep 挂起、coro_destroy 帧回池
+#   M4: raise 存码、await 子帧异常传播、coro_exception 查询
+#   M5/M6: try/except（链式匹配 + as e 绑定异常码 + 类型码）
+#   M7: try/finally、异常消息 msg 槽、自定义异常类、帧池复用
+class MyError(Exception):
+    pass
+
+
+async def leaf(x: int) -> int:
+    return x * 2
+
+
+async def task(n: int) -> int:
+    s: int = 0
+    for i in range(3):                 # M3：For 内 await
+        s = s + await leaf(i)
+    if s > 4:
+        await coro.coro_sleep(5)       # M3：coro_sleep 挂起（wake 槽 + 轮询）
+    try:
+        raise ValueError("boom")       # M4/M6：raise 类型 + M7 消息
+    except ValueError as e:            # M5/M6：as e 绑定异常码
+        s = s + e
+    return s
+
+
+async def raiser() -> int:
+    try:
+        raise MyError("fin_msg")       # M7：自定义异常类 + 消息
+    finally:
+        x: int = 99                    # M7：finally 正常路径执行
+    return 0
+
+
+def main() -> int:
+    tt: t.CPtr = task(3)
+    r: int = coro.coro_run(tt)
+    e: int = coro.coro_exception(tt)
+    stdio.printf("coro result = %d exc = %d\n", r, e)
+    coro.coro_destroy(tt)              # M3/M7：destroy 回池
+    t1: t.CPtr = raiser()
+    r1: int = coro.coro_run(t1)
+    e1: int = coro.coro_exception(t1)
+    m1: t.CPtr = coro.coro_exception_msg(t1)
+    stdio.printf("coro result = %d exc = %d msg = %s\n", r1, e1, m1)
+    coro.coro_destroy(t1)
+    t2: t.CPtr = raiser()              # 帧池复用
+    r2: int = coro.coro_run(t2)
+    e2: int = coro.coro_exception(t2)
+    stdio.printf("coro result = %d exc = %d\n", r2, e2)
+    coro.coro_destroy(t2)
+    return 0