Using 'uglify: true' breaks the output for IE 11

[zhaparoff]

When uglify: true, output is transformed in the way, which produces runtime errors in IE 11.

For example, undefined check:

typeof varName1 !== "undefined"

is transformed to:

0 !== varName1 

which fails with "Wrong number of arguments or invalid property assignment" error at runtime.

Most likely, related to the mishoo/UglifyJS#2813