LibJS: Make SetCompletionType bytecode instruction actually set type

This recovers 38 tests in test262 that regressed in a0bb31f7a0.

Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -3847,7 +3847,7 @@ void SetCompletionType::execute_impl(Bytecode::Interpreter& interpreter) const
 {
     auto& completion_cell = static_cast<CompletionCell&>(interpreter.get(m_completion).as_cell());
     auto completion = completion_cell.completion();
-    completion_cell.set_completion(Completion { completion.type(), completion.value() });
+    completion_cell.set_completion(Completion { m_type, completion.value() });
 }
 
 ByteString SetCompletionType::to_byte_string_impl(Bytecode::Executable const& executable) const

Libraries/LibJS/Tests/regress/async-generator-function-set-completion-type.js

@@ -0,0 +1,43 @@
+test("test", () => {
+    var obj = {
+        [Symbol.iterator]() {
+            return {
+                next() {
+                    return { value: 1, done: false };
+                },
+            };
+        },
+    };
+
+    async function* asyncg() {
+        yield* obj;
+    }
+
+    let fail = false;
+    let done = false;
+
+    function FAIL() {
+        fail = true;
+    }
+
+    function DONE() {
+        done = true;
+    }
+
+    var iter = asyncg();
+
+    iter.next()
+        .then(function (result) {
+            iter.return()
+                .then(function (result) {
+                    expect(result.done).toBeTrue();
+                    expect(result.value).toBeUndefined();
+                })
+                .catch(FAIL);
+        })
+        .catch(FAIL)
+        .then(DONE);
+    runQueuedPromiseJobs();
+    expect(fail).toBe(false);
+    expect(done).toBe(true);
+});