`rewriteRelativeImportExtensions` not working with inline `await import`

[jsteelz]

Describe the bug

swc is leaving a trailing _ts_rewrite_relative_import_extension wrapper on await import statements when using rewriteRelativeImportExtensions: true option in jsc.

This is not expected for me and predictably causes ReferenceError: _ts_rewrite_relative_import_extension is not defined when running output code.

Please excuse me if I've mis-configured or missed something.

Input code

import path from 'path';
import fs from 'fs-extra';

export async function loadNode(file: string) {
  const pathToFile = path.resolve('base', `${file}.ts`);
  if (await fs.pathExists(pathToFile)) {
    const { default: _default, ...rest } = await import(pathToFile);
    return rest;
  }
  return {};
}

Config

{
  "$schema": "https://swc.rs/schema.json",
  "jsc": {
    "parser": {
      "syntax": "typescript",
      "tsx": false,
      "decorators": true,
      "dynamicImport": true
    },
    "rewriteRelativeImportExtensions": true,
    "target": "es2024",
  },
  "module": {
    "type": "es6"
  },
  "sourceMaps": true,
  "isModule": true
}

Link to the code that reproduces this issue

https://play.swc.rs/?version=1.13.20&code=H4sIAAAAAAAAA02PMU%2FDMBCFd%2F%2BKG5CSSK3ZGzHCiBjYW5OcwVJqV74LDbL83%2FHFKWU7v%2FfufWd3voTIcDH8BTaGMzQyNr1y1bC0yZb2uHA0dyt9GMK3ks5bRD%2BKspcCzdQohcsaNPTjB7CzH9gFD1Mw42sYsbVuwgMQR%2Bc%2FO0gKYAie6jHv4aW48LQ%2BdEQK0ze2N%2BIOTg9J1nMBnbq%2BrDoLrbkaJydrWXpeHDG197KuMm6UBCNaM098gOM27UBrYTHkQq5t9bP%2Fa%2Fq1JCLP0YOkRcjqT0q5V1n9AkCRo3tZAQAA&config=H4sIAAAAAAAAA02OOw7CQAxEe04RWZSIoAhR0FNQ0HCD1cbAouxHtgNEUe7OfiDQ2Z434xkXVQVL1je0CvYV3EQC7%2Buan3pNXBdhfWfvYJXQO%2BuIjXGMS1DESPMeLzw4Ua8UJENA1mSCZGNWhZN0UR3jfGsHp6zRRxs8SVSFeszaVBAgfJIRPGOnxDywgIeXoGPjHX8sH1gUXTHFAHKzabb5d04C69u%2Bw1%2F5VLCAO5gh9j1pPKnwnwuGT19zrjct3tn52CI3AQAA

SWC Info output

No response

Expected behavior

The await import statement should be left as is, or if transforming is done, there should not be a leftover _ts_rewrite_relative_import_extension in the output.

Actual behavior

_ts_rewrite_relative_import_extension is left in the output, but this is never defined.

Version

1.13.20

Additional context

Originally encountered on 1.15.3, but swc-playground indicates it is still occurring in latest.