Determines if an expression statement needs to be surrounded by parentheses.
The statement or the left-most expression needs to be surrounded by
parentheses if the left-most expression is an object literal or a function
object.
Precedence indices from "JavaScript - The Definitive Guide" 4th Edition (page
57)
Precedence 17 is for indivisible primaries that either don't have children,
or provide their own delimiters.