JIT: session_destroy LLVM lowering (session_regenerate_id done #1895)

[PurHur]

Problem

#1186 ✅ closed (#1895 — session_regenerate_id JIT/AOT on master). session_destroy still throws in JIT builds:

'session_destroy() not implemented for JIT in this compiler build (issue #1182)'

docs/capabilities.md correctly lists JIT no; SelfHostBuiltinPolicy maps both to session stubs. 005-SessionsWeb (#1881) logout/regenerate flows need JIT parity for spine/self-host and honest phpc serve --jit (#207).

session_start / session_write_close landed in #1882 / #1890 — reuse the same C runtime (lib/AOT/runtime/phpc_session_lifecycle.c) and lib/JIT/Builtin/Session*.php pattern.

Goal

• session_destroy() compiles under JIT/AOT without LogicException (session_regenerate_id ✅ Stdlib: LLVM JIT/AOT for session_regenerate_id() (#1186) #1895)
• PHPT compliance cases (mirror session_start_jit.phpt)
• Regenerate docs/capabilities.md → JIT yes for session_destroy (regenerate already yes)

Implementation hints

Piece	Path	Notes
VM	ext/standard/session_destroy.php, session_regenerate_id.php	Already correct
LLVM stubs	lib/JIT/Builtin/SessionDestroy.php (new)	SessionRegenerateId.php ✅ #1895; register like SessionStart
C runtime	lib/AOT/runtime/phpc_session_lifecycle.c	Extend destroy helper (regenerate helpers ✅ #1895)
Self-host	lib/JIT/SelfHostBuiltinPolicy.php	Move from stub → real lowering when safe
Tests	test/compliance/cases/stdlib/session_destroy_jit.phpt	Two-request destroy clears $_SESSION
Audit	php script/audit-stdlib-jit.php	Update docs/stdlib-jit-audit.md

Acceptance criteria

./script/ci-local.sh --filter 'session_destroy|session_regenerate'
vendor/bin/phpunit test/compliance/cases/stdlib/session_destroy_jit.phpt
php script/capability-matrix.php   # JIT yes for both

Docker:

docker run --rm -v "$(pwd):/compiler" -w /compiler php-compiler:22.04-dev \
  ./script/ci-local.sh --filter SessionDestroy

Dependencies

• JIT: session_start lowering for self-host spine (ext/standard/session_start.php) #1882 ✅ session_start JIT pattern
• Stdlib: session_start() and $_SESSION (file or memory driver) #64 ✅ VM sessions
• Examples: 005-SessionsWeb — session_start + flash message reference app #1881 — consumer example (logout route)

Links

• Closed VM issues: Stdlib: session_destroy() — VM + LLVM JIT/AOT #1182, Stdlib: session_regenerate_id() — VM + LLVM JIT/AOT #1186
• ROADMAP #78 Phase 2 Stdlib
• Wave 3 stdlib tracker #1380

[PurHur]

Batch 84 triage (PM, no implementation):

session_regenerate_id JIT/AOT landed on master via #1895 (closes #1186). docs/capabilities.md on master already shows JIT yes for session_regenerate_id.

Remaining scope for this issue: session_destroy only — still JIT no (SelfHostBuiltinPolicy stub; no lib/JIT/Builtin/SessionDestroy.php yet).

Suggested follow-up PR title: JIT: session_destroy LLVM lowering (#1892)

Consumer: #1881 logout route can use regenerate now; destroy path still VM-only until this closes.