[mypyc] Test function nesting with async functions (#19203)

This only adds tests.

Author: JukkaL

mypyc/test-data/run-async.test

@@ -561,3 +561,85 @@ def test_bool() -> None:
 
 [file asyncio/__init__.pyi]
 def run(x: object) -> object: ...
+
+[case testRunAsyncNestedFunctions]
+import asyncio
+from typing import cast, Iterator
+
+from testutil import assertRaises
+
+def normal_contains_async_def(x: int) -> int:
+    async def f(y: int) -> int:
+        return x + y
+
+    return 5 + cast(int, asyncio.run(f(6)))
+
+def test_def_contains_async_def() -> None:
+    assert normal_contains_async_def(3) == 14
+
+async def inc(x: int) -> int:
+    return x + 1
+
+async def async_def_contains_normal(x: int) -> int:
+    def nested(y: int, z: int) -> int:
+        return x + y + z
+
+    a = x
+    a += nested((await inc(3)), (await inc(4)))
+    return a
+
+def test_async_def_contains_normal() -> None:
+    assert normal_contains_async_def(2) == (2 + 2 + 4 + 5)
+
+async def async_def_contains_async_def(x: int) -> int:
+    async def f(y: int) -> int:
+        return (await inc(x)) + (await inc(y))
+
+    return (await f(1)) + (await f(2))
+
+def test_async_def_contains_async_def() -> None:
+    assert asyncio.run(async_def_contains_async_def(3)) == (3 + 1 + 1 + 1) + (3 + 1 + 2 + 1)
+
+async def async_def_contains_generator(x: int) -> tuple[int, int, int]:
+    def gen(y: int) -> Iterator[int]:
+        yield x + 1
+        yield x + y
+
+    it = gen(4)
+    res = x + 10, next(it), next(it)
+
+    with assertRaises(StopIteration):
+        next(it)
+
+    return res
+
+def test_async_def_contains_generator() -> None:
+    assert asyncio.run(async_def_contains_generator(3)) == (13, 4, 7)
+
+def generator_contains_async_def(x: int) -> Iterator[int]:
+    async def f(y: int) -> int:
+        return (await inc(x)) + (await inc(y))
+
+    yield cast(int, asyncio.run(f(2)))
+    yield cast(int, asyncio.run(f(3)))
+    yield x + 10
+
+def test_generator_contains_async_def() -> None:
+    assert list(generator_contains_async_def(5)) == [6 + 3, 6 + 4, 15]
+
+async def async_def_contains_two_nested_functions(x: int, y: int) -> tuple[int, int]:
+    def f(a: int) -> int:
+        return x + a
+
+    def g(b: int, c: int) -> int:
+        return y + b + c
+
+    return (await inc(f(3))), (await inc(g(4, 10)))
+
+def test_async_def_contains_two_nested_functions() -> None:
+    assert asyncio.run(async_def_contains_two_nested_functions(5, 7)) == (
+        (5 + 3 + 1), (7 + 4 + 10 + 1)
+    )
+
+[file asyncio/__init__.pyi]
+def run(x: object) -> object: ...