Teach Ninja generator about 'AR.host' specified in 'make_global_settings'.

With this CL, Ninja generator starts recognizing 'AR.host' specified in 'make_global_settings', like Make generator.

BUG=gyp:434
TEST=unittest
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/333353002

git-svn-id: http://gyp.googlecode.com/svn/trunk@1942 78cadc50-ecff-11dd-a971-7dbc132099af
2 files changed