Add tests for Reflect.getOwnPropertyDescriptor

...lect/getOwnPropertyDescriptor/getOwnPropertyDescriptor.js

test/built-ins/Reflect/getOwnPropertyDescriptor/length.js

test/built-ins/Reflect/getOwnPropertyDescriptor/name.js

...tOwnPropertyDescriptor/return-abrupt-from-property-key.js

...ect/getOwnPropertyDescriptor/return-abrupt-from-result.js

...tOwnPropertyDescriptor/return-from-accessor-descriptor.js

...t/getOwnPropertyDescriptor/return-from-data-descriptor.js

...t-ins/Reflect/getOwnPropertyDescriptor/symbol-property.js

...t/getOwnPropertyDescriptor/target-is-not-object-throws.js

...flect/getOwnPropertyDescriptor/target-is-symbol-throws.js

...eflect/getOwnPropertyDescriptor/undefined-own-property.js

...ns/Reflect/getOwnPropertyDescriptor/undefined-property.js