Self-host M2: land final 3 ext/standard Vm* units in compiler_lib_spine_smoke (578→586)

[PurHur]

Problem

After #1818 hygiene, 3 open m2-spine-unit issues remain — all AOT lint blockers for spine growth:

Issue	File
#1540	ext/standard/VmPregReplaceCallback.php
#1543	ext/standard/VmSplAutoload.php
#1544	ext/standard/VmString.php

compiler_lib_spine_smoke is 578/586 inventory files on master. These three units block closing the M2 spine gap toward full lib/ link (#1419, #1492).

Goal

Bundle PR adds all three files to test/selfhost/compiler_lib_spine_smoke/main.php with:

• php bin/compile.php -l green on the spine bundle
• BOOTSTRAP_LIB_SPINE_SMOKE=1 make bootstrap-selfhost-lib-spine-smoke link OK
• Close M2 spine: add ext/standard/VmPregReplaceCallback.php to compiler_lib_spine_smoke #1540, M2 spine: add ext/standard/VmSplAutoload.php to compiler_lib_spine_smoke #1543, M2 spine: add ext/standard/VmString.php to compiler_lib_spine_smoke #1544
• Update counts to 586/586 in BootstrapSelfhostBundleTest, docs/bootstrap-inventory.md, ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78

array_multisort remains deferred (#1809 notes Expr_Closure in comparator) — separate from this bundle.

Implementation hints

Step	Command
Lint one file	php bin/compile.php -l ext/standard/VmString.php
Lint spine	php bin/compile.php -l test/selfhost/compiler_lib_spine_smoke/main.php
Native link	BOOTSTRAP_LIB_SPINE_SMOKE=1 make bootstrap-selfhost-lib-spine-smoke
Inventory	php script/bootstrap-inventory.php --check

Likely touch: lib/JIT/Builtin/, SelfHostBuiltinPolicy, spine require_once list.

Acceptance criteria

make bootstrap-wave-check
BOOTSTRAP_LIB_SPINE_SMOKE=1 make bootstrap-selfhost-lib-spine-smoke
M2_SPINE_ISSUE_HYGIENE_GATE=1 php script/check-m2-spine-issue-hygiene.php
grep -c '^require_once' test/selfhost/compiler_lib_spine_smoke/main.php   # 586

Docker:

docker run --rm -v "$(pwd):/compiler" -w /compiler php-compiler:22.04-dev \
  bash -lc 'BOOTSTRAP_LIB_SPINE_SMOKE=1 make bootstrap-selfhost-lib-spine-smoke'

Dependencies

• M2 spine growth: batch tracker (compiler_lib_spine_smoke → full inventory) #1419 batch tracker
• Self-host M3: HashTable rehash for native AOT runtime (#66 → #1514) #1761 hashtable (M3 emit) — orthogonal but shares VM builtins
• Hygiene DevEx: M2 spine open-issue hygiene guard (#1808) #1818 ✅

Links

• Epic Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 · ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 Phase 5

[PurHur]

PM note — batch 78 (reopen criteria)

Closed 2026-05-25 targeting 578→586 for #1540 / #1543 / #1544.

Master today: compiler_lib_spine_smoke/main.php has 585 require_once lines; BootstrapSelfhostBundleTest asserts 584; inventory remains 588 files.

Do not reopen for doc-only drift. Reopen (or new child under #1419) when a PR will:

• Land remaining inventory files to 588/588 (or document explicit deferrals in bootstrap-inventory.md)
• Align test count with grep -c '^require_once' on the bundle
• Unblock CI: Default BOOTSTRAP_LIB_SPINE_VM_SMOKE_GATE=1 in ci-local (#1846 follow-up) #1867 default VM spine smoke gate

Tracked on ROADMAP #78 batch 78 and epic #1492.