Bundled import.meta.main should reflect loaded state.

[kitsonk]

Currently, during bundling the import.meta.main is set to true for the main module, but when that bundle is loaded, the main module might not be loaded as the main module and so the import.meta.main should be false.

[kitsonk]

This appears not to be possible as long as we use the system loader for the snapshots, because use of the import keyword throws outside of a module, and there is no way to safely access it, and we have to compare the runtime import.meta.main to the bundled main module.

[kitsonk]

This is potentially possible now that system_loader.js isn't being used for the snapshots and deno_typescript is gone, so this can be revisited.

[kitsonk]

This was fixed with #8058.