[codex] Align function prototype value reads

[andrewtdiz]

Summary

Addresses #2768 and #3877.

This aligns direct ordinary function .prototype value reads for local function values so codegen routes FuncRef/closure prototype reads through the runtime materialization path. That gives Object.create(Foo.prototype) and Reflect.construct(..., newTarget) an object value instead of the previous non-object result, while preserving dynamic/deleted prototype properties and generator function prototype handling.

The PR also adds a focused object parity fixture for ordinary function prototype values, assigned prototype objects, Object.create(Foo.prototype), and arrow-function absence.

Why Batched

Both issues hit the same runtime/codegen invariant: construct/proxy/object creation flows depend on newTarget.prototype or Foo.prototype being an object when an ordinary function exposes its default prototype. Keeping them together avoids splitting one semantic fix across duplicate reflect/proxy symptoms.

Validation

• PERRY_NO_AUTO_OPTIMIZE=1 npm exec --yes --package=node@26 -- bash -lc 'node --version; ./run_parity_tests.sh --suite node-suite --module object --filter function-prototype-value'
• PERRY_NO_AUTO_OPTIMIZE=1 npm exec --yes --package=node@26 -- bash -lc 'node --version; ./run_parity_tests.sh --suite node-suite --module object --filter reflect-proxy-construct'
• Direct Node/Perry output diff for test-parity/node-suite/object/function-prototype-value.ts
• Direct Node/Perry output diff for test-parity/node-suite/object/reflect-proxy-construct.ts
• cargo fmt --all -- --check
• git diff --check
• ./scripts/check_file_size.sh

cargo build --release --quiet -p perry -p perry-runtime -p perry-stdlib passed on the code-bearing diff before the final comment-only cleanup. A later retry after that cleanup was interrupted by SIGTERM while another release job was running in a separate worktree.

Known Limitations

This intentionally keeps the cut narrow. Imported function .prototype value reads and broader inherited-property behavior through objects created from Foo.prototype are left as follow-up work; this PR fixes the local FuncRef/closure value-read tail that blocks the focused reflect/proxy construct parity fixture.