Features: run feature detector to verify newly added feature flags

test/built-ins/Proxy/construct/trap-is-null.js

...uilt-ins/Proxy/construct/trap-is-undefined-no-property.js

test/built-ins/Proxy/construct/trap-is-undefined.js

...ons/arrow-function/lexical-new.target-closure-returned.js

...language/expressions/arrow-function/lexical-new.target.js

...anguage/expressions/new.target/value-via-reflect-apply.js

...age/expressions/new.target/value-via-reflect-construct.js

...guage/expressions/new.target/value-via-tagged-template.js

test/language/expressions/super/call-construct-invocation.js