Changes the ninja generator to output phony targets for uninteresting targets

Changes the ninja generator to output phony targets for uninteresting targets

This way you can pass these targets to the build system and not get
errors.

BUG=410410
TEST=covered by test now
R=thakis@chromium.org

Committed: https://code.google.com/p/gyp/source/detail?r=1973

[sky, 2014-09-04 17:49:27]

sky@chromium.org changed reviewers:
+ thakis@chromium.org

[Nico, 2014-09-04 17:55:14]

lgtm if the test passes on all build systems.

Thanks!

[sky, 2014-09-04 23:59:29]

I'm going to land. My first try failed on gyp-win64, but my second try passed.
Seems like flake unrelated to my change as the failure was in msvs-2010.

[sky, 2014-09-04 23:59:57]

Committed patchset #1 (id:1) manually as r1973 (presubmit successful).

[jochen (gone - plz use gerrit), 2014-09-08 08:04:45]

jochen@chromium.org changed reviewers:
+ jochen@chromium.org

[jochen (gone - plz use gerrit), 2014-09-08 08:04:45]

this broke compilation, as we now output empty phony rules for already existing
rules.