Svelte 5: error if there are two spaces after `@const`

[ota-meshi]

Describe the bug

When defining {@const} using Svelte v5 preview, two spaces after the @const keyword will result in an error. There is no problem if there is only one space. There is also no problem with Svelte v4.

Reproduction

e.g.

<script>
    let list = [1, 2, 3];
</script>

{#each list as e}
    {@const  a = e * 2}
    {e} * 2 = {a}<br>
{/each}

https://svelte-5-preview.vercel.app/#H4sIAAAAAAAAEz2OTQrCMBCFrzKMOwkU665G0XO0XcR0ioE0DUkqSMjdnVB0du97P0zG2ViK2PUZnVoIO3x4jwLTx1cR32QTsY7rFnQlMupgfLoNDvgsJbAmJrhCfxLQCjiPl8HJ5p8aXD6Q0q89piJQ2av5rlfHCBSXCY7Q_gwqVTHNqshn4JHc1An2-ZNlncxsaMIuhY3KWL7fRWigxAAAAA==

Logs

Error compiling App.svelte
{@const ...} must be an assignment
line 6 column 4

System Info

System:
    OS: macOS 13.2.1
    CPU: (8) x64 Intel(R) Core(TM) i5-8259U CPU @ 2.30GHz
    Memory: 83.73 MB / 16.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 18.18.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 9.8.1 - /usr/local/bin/npm
    pnpm: 8.5.0 - /usr/local/bin/pnpm
  Browsers:
    Chrome: 119.0.6045.199
    Safari: 16.3
  npmPackages:
    svelte: ^5.0.0-next.15 => 5.0.0-next.15

Severity

annoyance