Parser misinterprets async() calls in conditional expressions as async arrow functions

还没有人认领这个 Issue。

### 🔎 Search Terms

parser, async, conditional

### 🕗 Version & Regression Information

- This is the behavior in every version I tried

### ⏯ Playground Link

_No response_

### 💻 Code

```ts
const a = true;
const b = 1;

function async(): number {
return b;
}

const first = a ? async() : 0;
// TS1005: '=>' expected.

const second = a ? async() : x => x;
// TS1005: ':' expected.
```

### 🙁 Actual behavior

The parser appears to interpret async() as the beginning of an async arrow function and the conditional separator as a return-type annotation.
The first case also produces a syntax diagnostic when parsed as JavaScript after removing the : number annotation. Node accepts and executes that JavaScript equivalent

### 🙂 Expected behavior

Both conditional expressions should parse successfully. async() is a call to the function named async, and the following colon separates the conditional’s branches.

### Additional information about the issue

Oxc fix: https://github.com/oxc-project/oxc/pull/26537

首先在 TypeScript 解析器中复现两个条件表达式示例，并比较 async() 与 async 箭头函数的分类方式。参考链接的 Oxc 修复来了解相关的解析行为。完成标准是两个示例都能成功解析且不再出现报告中的诊断，并且为所示案例添加回归覆盖。

由索引模型根据 Issue 内容生成。