feat(ffi): enable bun:ffi on FreeBSD

[mfwolffe]

What does this PR do?

Enable TinyCC and bun:ffi dlopen() on FreeBSD. The vendored TinyCC
fork already has full FreeBSD ELF support (TARGETOS_FreeBSD, note
sections, ld-elf.so.1 interp) but was excluded from the build.

Changes:

• config.ts / buildOptionsRs.ts: remove FreeBSD from tinycc exclusion
• tinycc.ts: set TARGETOS_FreeBSD define
• tcc.rs: remove FreeBSD from cfg-gated extern stubs
• tools.ts: add FreeBSD LLVM paths and name variants (clang21, lld21),
  wire up ld.lld and strip resolution

How did you verify your code works?

Full build from source on FreeBSD 15.0 x86_64 with LLVM 21.1.8 and
Rust nightly-2026-05-06. bun:ffi dlopen() loads a Zig-compiled .so
and the resulting binary passes the version smoke test.

[claude]

Claude Code Review

This pull request is from a fork — automated review is disabled. A repository maintainer can comment @claude review to run a one-time review.

[coderabbitai]

Actionable comments posted: 0

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 281ea42 and 22b7074.

📒 Files selected for processing (1)

• src/runtime/ffi/mod.rs

💤 Files with no reviewable changes (1)

• src/runtime/ffi/mod.rs

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Walkthrough

FreeBSD is removed from TinyCC-disable gating; TinyCC can be enabled on FreeBSD. Build defines add TARGETOS_FreeBSD. LLVM discovery and tool selection are extended for FreeBSD. tcc FFI now emits real extern declarations on FreeBSD instead of stubs.

Changes

FreeBSD TinyCC and LLVM support

Layer / File(s)	Summary
TinyCC feature gating for FreeBSD scripts/build/buildOptionsRs.ts, scripts/build/config.ts	FreeBSD is removed from conditions that disable TinyCC, altering the generated ENABLE_TINYCC predicate and default cfg.tinycc.
TinyCC DirectBuild target configuration scripts/build/deps/tinycc.ts	FreeBSD-specific target define TARGETOS_FreeBSD is added to the TinyCC DirectBuild defines map.
LLVM toolchain discovery for FreeBSD scripts/build/tools.ts	LLVM search paths include FreeBSD standard and ports directories; name variants include ports-style suffix; linker and strip selection adopt Linux-style resolution for FreeBSD.
TinyCC FFI symbol declarations for FreeBSD src/tcc_sys/tcc.rs, src/runtime/ffi/mod.rs	tcc_externs! cfg logic and TCC::tcc_delete gating now generate real unsafe extern "C" declarations on FreeBSD; Android and Windows/aarch64 remain stubbed.

Possibly related PRs

• oven-sh/bun#30749: Modifies ENABLE_TINYCC constant generation in scripts/build/buildOptionsRs.ts with related platform-gating changes.
• oven-sh/bun#30743: Adjusts TinyCC FFI symbol wiring via target-specific extern declarations for consistency with bun_tcc_sys support.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly describes the main objective: enabling bun:ffi on FreeBSD, which aligns with all changes across the codebase.
Description check	✅ Passed	The description includes both required sections with comprehensive details: 'What does this PR do?' explains the feature and lists changes; 'How did you verify?' documents the build environment and testing.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/tcc_sys/tcc.rs`:
- Around line 34-40: The runtime FFI gating is out of sync with tcc_sys: in
mod.rs update the cfg attributes so FreeBSD is treated the same as in
tcc_sys—remove "target_os = \"freebsd\"" from the #[cfg(not(any(...)))] that
wraps the real extern "C" block and from the #[cfg(any(...))] that provides the
tcc_delete unreachable! stub; instead enable the real extern "C" bindings on
FreeBSD and replace the stubbed tcc_delete with the forwarding implementation
that calls into the tcc_sys binding (use the same extern symbol names and the
tcc_delete function identifier) so FreeBSD uses the real TinyCC FFI rather than
panicking.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

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Configuration used: Path: .coderabbit.yaml

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📥 Commits

Reviewing files that changed from the base of the PR and between c731fe9 and 281ea42.

📒 Files selected for processing (5)

• scripts/build/buildOptionsRs.ts
• scripts/build/config.ts
• scripts/build/deps/tinycc.ts
• scripts/build/tools.ts
• src/tcc_sys/tcc.rs

💤 Files with no reviewable changes (1)

• scripts/build/buildOptionsRs.ts

[coderabbitai]

Actionable comments posted: 0