Self-host P0: JIT external class method calls in bundled lib (PhpParser, etc.)

[PurHur]

Blocks

Self-host bundle AOT hits undefined external methods, e.g.:
Call to undefined method phpparser\nodetraverser::addvisitor

Bundled lib/Compiler.php uses vendor types at runtime; JIT must proxy or stub external ->method() calls used in the minimal closure.

Goal

Minimal fix: JIT TYPE_METHODCALL / static dispatch for external classes used in bundle (start with PhpParser NodeTraverser::addVisitor or defer via compile-time stubs).

Acceptance

• Document which external APIs are stubbed vs implemented
• Progress toward ./script/bootstrap-selfhost-link.sh (Self-host P0: JIT __value__ / hashtable paths for Block::scopeOperandBySlot #557)

Non-goals

• Compiling full vendor/nikic/php-parser