mishoo/UglifyJS — pull request #370 by mal (2012-04-21 20:19:39+00:00)
Title: RFC: Squash directives when already active in higher scope

This removes directives from the AST if the same directive has been activated in a higher scope. As this is scope dependent, the changes are made in `ast_add_scope` rather than `ast_squeeze` which at present has no scope awareness. The upshot of which is that this optimisation currently only works when mangling.

If you think it would be better to introduce scope awareness to `ast_squeeze` and handle it in there, let me know.

Feedback welcome!