Compiler: Register JIT-stubbed switch in UnsupportedRegistry (lint parity)

[PurHur]

Problem

switch works in the VM but JIT leaves TYPE_CASE stubbed (#96). phpc lint may still report exit 0 for router scripts using switch, so #246 MiniWebApp lint-first workflow misleads contributors until JIT compile fails later.

docs/unsupported-syntax.md lists loops/?? but not switch or JIT-only gaps.

Goal

When lint runs in JIT-aware mode (or by default for project lint #283), flag Stmt_Switch / switch CFG nodes with tracking issue #96 unless JIT implementation lands.

Minimal path: always report switch as unsupported for AOT/JIT deploy until #96 closes (VM-only apps can document exception).

Scope

• Add Stmt_Switch (and case bodies if needed) to lib/Lint/UnsupportedRegistry.php
• Update docs/unsupported-syntax.md table
• test/unit/UnsupportedRegistryTest.php or lint PHPT: switch exits 1 with see #96
• Optional --target=vm|jit|aot flag on phpc lint (stretch; default VM-only OK for phase 1)

Acceptance criteria

./phpc lint -r 'switch (1) { case 1: echo 1; }'

Exit code 1; stderr/JSON references #96.

Verification

./script/ci-local.sh --filter Lint

Local/Docker only — no GitHub Actions.

Dependencies

• JIT: Implement switch/case opcodes (TYPE_CASE) — VM works, JIT stubbed #96 switch JIT implementation (closes lint gap)
• test(aot): add array_shift LLVM compile-and-run PHPT #283 project lint (consumer)
• Reference: MiniWebApp lint-first skeleton (examples/003-MiniWebApp) #246 MiniWebApp blocker table

Links

• lib/Lint/UnsupportedRegistry.php, lib/JIT.php, lib/Compiler.php