Self-host Phase D: AOT link first namespaced lib/ translation unit

[PurHur]

Problem

Self-host Phase A–C are green (docs/bootstrap-selfhost.md, #512–#520 ✅): procedural test/bootstrap-aot/*, namespace_hello.php, class constants, native link smoke.

The compiler itself lives under namespace PHPCompiler; in lib/. #84 / #513 closed namespace parsing for small fixtures, but no issue tracks linking a real lib/ file (e.g. lib/OpCode.php or lib/Frame.php) as a native binary.

Goal

Add Phase D gate:

make bootstrap-aot-link-lib   # new target
# links one namespaced lib/*.php subset; stdout matches Zend on fixture input

Scope

• Pick smallest linkable unit after Language: Class methods and property access in JIT #58/Language: Visibility, constructors, and destructors #145 (inventory: lib/OpCode.php lints; lib/Frame.php needs ClassMethod)
• Extend script/bootstrap-aot-link.sh with lib_opcode (or similar) target
• Document in docs/bootstrap-selfhost.md + 🗺️ ROADMAP: Compile a small PHP web application (living document) #78 Phase 0 stretch
• @group llvm test or script check in ci-local.sh (optional, skipped without LLVM)

Acceptance criteria

docker run --rm -i -w /compiler php-compiler:22.04-dev bash -lc '
  tar -xf - 2>/dev/null
  make bootstrap-aot-link-lib
'

Exit 0; linked binary runs without Zend for the fixture.

Verification (local / Docker only)

php script/bootstrap-inventory.php --check
php script/bootstrap-aot-lint.php
make bootstrap-aot-link-lib

Dependencies

• Language: Class methods and property access in JIT #58, Language: Visibility, constructors, and destructors #145 for lib/Frame.php-class units
• Language: try/catch/finally lowering #57 try/catch before lib/Runtime.php
• Language: PHP namespaces (namespace, use, qualified names) #84 namespaces ✅

Non-goals

• Compiling full lib/Compiler.php in one TU (AOT: Link multiple translation units into one binary #154 multi-TU stretch)
• Self-hosting vendor/

Links

• Parent index Milestone: Self-host — compile php-compiler with php-compiler (bootstrap) #212 (closed milestone)
• 🗺️ ROADMAP: Compile a small PHP web application (living document) #78 ROADMAP