TypeScript: an exported variable of sibling namespaces can not be correctly transformed when assigned

Example input code:

```ts
namespace A {
export var x = 0;
}

namespace A {
console.log(x);
x = 0;
}
```

TypeScript 6.0.2 ([playground][pg1]):

[pg1]: https://www.typescriptlang.org/play/?target=7&module=1&ts=6.0.2#code/HYQwtgpgzgDiDGEAEBBJBvAUEnSIA8YB7AJwBckA3EEpfJAXiQAYBuTAX001ElgWRosuJPCLAoRADYQAdFKIBzABT4AlOxH0mbTkA

```js
"use strict";
var A;
(function (A) {
A.x = 0;
})(A || (A = {}));
(function (A) {
console.log(A.x);
A.x = 0;
})(A || (A = {}));
```

esbuild 0.28.0 ([playground][pg2]):

[pg2]: https://esbuild.github.io/try/#dAAwLjI4LjAALS1sb2FkZXI9dHMAbmFtZXNwYWNlIEEgewogICAgZXhwb3J0IHZhciB4ID0gMDsKfQoKbmFtZXNwYWNlIEEgewogICAgY29uc29sZS5sb2coeCk7CiAgICB4ID0gMDsKfQ

```js
var A;
((A2) => {
A2.x = 0;
})(A || (A = {}));
((A2) => {
console.log(A2.x);
x = 0;
})(A || (A = {}));
```

Related issue: #1410

Start by compiling the reported TypeScript namespace example with esbuild 0.28.0 and comparing its output with the TypeScript output shown. Trace how the sibling namespace assignment is transformed; done means the assignment targets the exported namespace variable rather than an unresolved bare identifier.

Written by the indexing model from the issue text.