Gen-1+ #1: Honest full-spine native compile without gen-0 sidecar fallback

[PurHur]

Problem

Gen-2 argv compile of compiler_lib_spine_smoke/main.php (3933 files) often logs parseAndCompile returned null and recovers via committed prelinked/bootstrap-gen0/.m3_compiler_lib_aot_blob. The bootstrap loop passes, but this is not honest native compile.

Acceptance

• build/bin-compile-aot-inventory -o OUT test/selfhost/compiler_lib_spine_smoke/main.php succeeds with no stderr containing recovered via gen-0 sidecar or sidecar emit fallback
• BOOTSTRAP_M5_NO_ZEND=1 path works for full-spine emit without Zend

Notes

• Tracker: JIT M3 allowlist / Runtime spine (M3: PHP_COMPILER_M3_COMPILE_DRIVER=1 link segfaults LLVM 9 during Runtime real lowering #1402, Self-host M4/M5: argv native bin-compile-aot compiles full spine without M3 sidecar env #2866)
• North-star epic: Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 · blocks gen-1+ only dev workflow · see docs/bootstrap-dev-workflow.md