ninja: Add .a files in a deterministic order to link lines.

The order even happens to match the one Xcode chooses.

BUG=280718
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/23439003

git-svn-id: http://gyp.googlecode.com/svn/trunk@1731 78cadc50-ecff-11dd-a971-7dbc132099af
ninja: Put generated sources in front of regular sources.

This matches the behavior of the xcode generator.  As sources are generated by
actions and rules which run before the regular compile phase of a target, this
is a bit more intuitive and so I changed the ninja generator instead of the
xcode generator.

BUG=chromium:280718
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/24167002

git-svn-id: http://gyp.googlecode.com/svn/trunk@1732 78cadc50-ecff-11dd-a971-7dbc132099af