v: add support for alignof.

[tritao]

Summary

This PR adds support for the alignof builtin, allowing users to get the memory alignment (in bytes) of a type or expression.

Highlights

• New AST node: AlignOf

• Supports both alignof(expr) and alignof[Type]()

• Integrated into:

  • Parser, checker, formatter (v fmt)

  • C codegen (via alignof(...) + <stdalign.h>)

  • JS backend (placeholder for now)

• Updated docs.md and changelog

This improves low-level memory control and brings alignof in line with sizeof.

I know this is missing tests, just want to make sure this is acceptable to add before I put more time into it.

[huly-for-github]

Connected to Huly®: V_0.6-22877

[felipensp]

Following this tip from CONTRIBUTING will helps you on next commits (it will do the v fmt on commit changed files to you):

cp cmd/tools/git_pre_commit_hook.vsh .git/hooks/pre-commit
chmod 755 .git/hooks/pre-commit

[tritao]

PR has been updated, can someone re-approve to run CI?

[enghitalo]

PR has been updated, can someone re-approve to run CI?

You need to format the code use v fmt w . for this

[tritao]

v fmt w .

That wasn't it, I think the files should be already formatted through the setup Git pre-commit hook. I just had an unintended change in fmt.v.

[tritao]

There is one pending job, what's the procedure to restart it?

[JalonSolov]

I tried... GitHub simply isn't allocating a runner to run it, so it will sit waiting until GitHub thinks it's OK.

[Delta456]

Shouldn't this be a checker error, not in code generation?

[spytheman]

(I've closed/reopened it to force the CI jobs to run again)

[JalonSolov]

Another close/reopen, due to expired logs.

[JalonSolov]

Yet another close/reopen. @tritao do you think you might finish this soon?