WIP async repl implementation

This now works:

    import asyncio
    import types

    print('here')

    L = {
        'asyncio': asyncio,
        'a': 'something'
    }

    code = compile('''
    async with asyncio.Lock():
        a = await asyncio.sleep(1, result=42)
    ''', '', 'single', 0x2000)

    f = types.FunctionType(code, L)

    print('before', L)
    asyncio.run(f())
    print('after', L)

Author: Yury Selivanov

Include/compile.h

@@ -23,6 +23,7 @@ PyAPI_FUNC(PyCodeObject *) PyNode_Compile(struct _node *, const char *);
 #define PyCF_ONLY_AST 0x0400
 #define PyCF_IGNORE_COOKIE 0x0800
 #define PyCF_TYPE_COMMENTS 0x1000
+#define PyCF_AWAIT 0x2000
 
 #ifndef Py_LIMITED_API
 typedef struct {

Python/compile.c

@@ -4551,7 +4551,9 @@ compiler_async_with(struct compiler *c, stmt_ty s, int pos)
 
     assert(s->kind == AsyncWith_kind);
     if (c->u->u_scope_type != COMPILER_SCOPE_ASYNC_FUNCTION) {
-        return compiler_error(c, "'async with' outside async function");
+        if (!(c->c_flags->cf_flags & 0x2000)) {
+            return compiler_error(c, "'async with' outside async function");
+        }
     }
 
     block = compiler_new_block(c);
@@ -4759,12 +4761,19 @@ compiler_visit_expr1(struct compiler *c, expr_ty e)
         ADDOP(c, YIELD_FROM);
         break;
     case Await_kind:
-        if (c->u->u_ste->ste_type != FunctionBlock)
-            return compiler_error(c, "'await' outside function");
+        if (c->u->u_ste->ste_type != FunctionBlock) {
+            if (!(c->c_flags->cf_flags & 0x2000)) {
+                return compiler_error(c, "'await' outside function");
+            }
+
+            c->u->u_ste->ste_coroutine = 1;
+        }
 
-        if (c->u->u_scope_type != COMPILER_SCOPE_ASYNC_FUNCTION &&
-                c->u->u_scope_type != COMPILER_SCOPE_COMPREHENSION)
-            return compiler_error(c, "'await' outside async function");
+        if (!(c->c_flags->cf_flags & 0x2000)) {
+            if (c->u->u_scope_type != COMPILER_SCOPE_ASYNC_FUNCTION &&
+                    c->u->u_scope_type != COMPILER_SCOPE_COMPREHENSION)
+                return compiler_error(c, "'await' outside async function");
+        }
 
         VISIT(c, expr, e->v.Await.value);
         ADDOP(c, GET_AWAITABLE);
@@ -5699,6 +5708,10 @@ compute_code_flags(struct compiler *c)
     /* (Only) inherit compilerflags in PyCF_MASK */
     flags |= (c->c_flags->cf_flags & PyCF_MASK);
 
+    if ((c->c_flags->cf_flags & 0x2000) && c->u->u_ste->ste_coroutine) {
+        flags |= CO_COROUTINE;
+    }
+
     return flags;
 }