fix(reflect): receiver-aware get, apply thisArg, construct newTarget, has chain, ownKeys symbols, setPrototypeOf failure

[proggeramlug]

Implements correct Node non-proxy semantics for six Reflect operations. Each behavior is asserted byte-for-byte against node --experimental-strip-types in test-files/test_gap_reflect_semantics2.ts under the default auto-optimize compile.

Closes #2766
Closes #2767
Closes #2764
Closes #2763
Closes #2761

Implementation

• runtime: make Reflect.get honor receiver and proxy get semantics #2766 Reflect.get(target, key, receiver): carry the optional receiver through HIR (ReflectGet gains a receiver field), codegen, and runtime. When key resolves to an accessor getter, the getter's this is rebound to the receiver via clone_closure_rebind_this (object-literal getters capture this in a reserved closure slot, so plain forwarding would read the target's fields). Throws TypeError for a non-object target.
• runtime: make Reflect.apply use thisArg, array-like args, and TypeErrors #2767 Reflect.apply(fn, thisArg, argumentsList): binds thisArg (through IMPLICIT_THIS), implements CreateListFromArrayLike (real Arrays via fast accessors, any other object via .length + indexed reads), throws TypeError for a non-callable target and for a non-object argumentsList.
• runtime: make Reflect.has use HasProperty semantics and proxy invariants #2764 Reflect.has(target, key): full HasProperty - own check plus a prototype-chain probe (via the inherited field read, which already walks Object.create/setPrototypeOf chains), TypeError on a non-object target, and ToBoolean normalization of proxy has trap results.
• runtime: make Reflect.ownKeys include symbols and honor proxy traps #2763 Reflect.ownKeys(target): returns string own-property names followed by own symbol keys, TypeError on a non-object target.
• runtime: make Reflect.setPrototypeOf report failed prototype changes #2761 Reflect.setPrototypeOf(target, proto): new ReflectSetPrototypeOf HIR variant (was hard-coded to Expr::Bool(true)). Returns a boolean (false when a non-extensible target rejects a changing prototype), throws TypeError for a non-object target or a proto that is neither object nor null. Shares the Object-side js_object_set_prototype_of side-table helper.

Dropped

• runtime: make Reflect.construct honor newTarget, array-like args, and constructor errors #2768 Reflect.construct newTarget: dropped. Honoring newTarget, array-like args, and constructor errors requires a real runtime construct-from-value path (constructing an arbitrary function/class value with a custom prototype), which Perry does not have today - non-proxy Reflect.construct only works through the compile-time fold to new ClassName(...). Left unchanged rather than ship a broken partial.
• Proxy three-argument get traps, ownKeys traps, and setPrototypeOf traps are out of scope (Perry's proxy traps are two-argument with no ownKeys/setPrototypeOf dispatch). The ordinary-object behavior is implemented; proxy targets fall through to their underlying target.

Validation

• test-files/test_gap_reflect_semantics2.ts is byte-identical to Node v25 (get-with-receiver+getter, apply thisArg+array-like+TypeErrors, has-on-inherited+TypeError, ownKeys-with-Symbol+TypeError, setPrototypeOf-on-preventExtensions'd to false + bad-arg TypeErrors).
• Regression: test_gap_proxy_reflect.ts and test_gap_reflect_2756_2762.ts stay byte-identical to Node.
• cargo test -p perry-hir (incl. expr_variant_stable_hash_tags_are_unique) and cargo test -p perry-runtime green.
• ./scripts/check_file_size.sh and cargo fmt --all -- --check clean.
• New Expr::ReflectSetPrototypeOf uses stable-hash tag 12230. Retention #[used] anchors added for the codegen-only reflect entry points; verified each symbol survives the auto-optimize whole-program bitcode rebuild.

HIR

• New variant Expr::ReflectSetPrototypeOf { target, proto } (tag 12230).
• New field receiver on the existing Expr::ReflectGet.