Determine if the JS environment has Symbol support. Supports spec, or shams.
An ES2015 mostly-spec-compliant Reflect.getPrototypeOf
sham/polyfill/replacement that works in as many engines as possible
Determine if the JS environment has Symbol.toStringTag
support. Supports spec, or shams.
An ES5 mostly-spec-compliant Object.getPrototypeOf
sham/polyfill/replacement that works in as many engines as possible
**This fork supports IE8 with es5-shim, es5-sham and es6-promise**