transpile: fix previously ignored enum usage in compound literals

[Yeaseen]

This is my first PR. I would appreciate any feedback.

• This pull request resolves c2rust Translation Failure with Enums in Compound Literals #1168.

Modification:

• Suggested changes mentioned in c2rust Translation Failure with Enums in Compound Literals #1168 were added in the c2rust-transpile/src/translator/literals.rs file
• Added a relevant C program in tests/enums/src/enum_compound.c file
• Modified tests/enums/src/test_enums.rs file to check the correct outputs

Testing

The added test case specifically checks for the correct assignment of enum values in buffer initialization using compound literals. This test has been integrated into the existing test suite and passed successfully, confirming the fix.

Please review the changes and provide feedback or approve the pull request. If further modifications are required, I am open to suggestions and will make the necessary adjustments.

Thank you for considering this contribution to improve the project's handling of enum types.

[Yeaseen]

@kkysen it seems the checks are passed. I would appreciate any feedback; thank you!

[kkysen]

Thanks for the PR! Congrats on your first PR!

It generally looks all good to me. I made a few suggestions for the test, but they're just little formatting/style things. The test itself looks good. The transpiler change @fw-immunant suggested looks good, though I don't know too much about that code, but if the test passes it should be good.

I also made a couple changes in the PR description directly. Notably, you need to use one of the GitHub issue closing keywords directly before mentioning the issue. So I deleted the "issue" in "resolves issue #1168".

[Yeaseen]

Thanks, @kkysen. I learned a lot from your edit in the description. Also, I updated the suggestions you made.