Translate GCC_C_LANGUAGE_STANDARD ansi to -ansi instead of -std=ansi

Because the latter doesn't exist.

BUG=none
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/21131007

git-svn-id: http://gyp.googlecode.com/svn/trunk@1685 78cadc50-ecff-11dd-a971-7dbc132099af