String.prototype.toUpperCase.hasOwnProperty('length') was failing with
'TypeError: hasOwnProperty is not a function' because js-invoke-method's
dict-with-builtin fallback only matched 'dict' receivers, not functions.
New js-invoke-function-objproto branch handles hasOwnProperty (checks
name/length/prototype keys), toString, valueOf, isPrototypeOf,
propertyIsEnumerable, toLocaleString. Fires from js-invoke-method when
recv is js-function? and key is in the Object.prototype builtin set.
Unblocks many String.prototype tests that check
.hasOwnProperty('length') on the prototype methods.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>