mishoo/UglifyJS2 — pull request #501 by Skalman (2014-06-30 23:00:12+00:00)
Title: Evaluate "foo".length ==> 3

This patch evaluates `"foo".length` into just `3`, i.e. `{string literal}.length` into a `{number}`.

The evaluation is done only when options `evaluate` and `unsafe` are on.