nl_tokens: Check given the variable name whether need to polyfill
pl_tokens: function shouldPolyfill ( importName , name , path ) { let result ; if ( Array . isArray ( importName ) ) { result = importName . some ( item => ( item === <mask> ) ) ; } else { result = importName === name ; } // ignore global variable, e.g., Array/Number/Promise etc. return result && ! path . scope . hasBinding ( name , true ) ; }