The option added in fbbaa42ee5 wasn't
being respected inside object literals, so quoted property names would
still be stripped out with this option.
This is mostly a corner-case, but useful when the output is passed to
something like the Closure compiler, where quoted property names can be
used to prevent mangling.
We only touch properties that are present in an object literal, or which are
assigned to. Example:
x = { foo: 1 };
x.bar = 2;
x["baz"] = 3;
x[cond ? "qwe" : "asd"] = 4;
console.log(x.stuff);
The names "foo", "bar", "baz", "qwe" and "asd" will be mangled, and the
resulting mangled names will be used for the same properties throughout the
code. The "stuff" will not be, since it's just referenced but never
assigned to.
This *will* break most of the code out there, but could work on carefully
written code: do not use eval, do not define methods or properties by
walking an array of names, etc. Also, a comprehensive list of exclusions
needs to be passed, to avoid mangling properties that are standard in
JavaScript, DOM, used in external libraries etc.
