xcodebuild: Fix most rebuild tests on Xcode 4.

BUG=chromium:175867
Review URL: https://codereview.chromium.org/12221156/

git-svn-id: http://gyp.googlecode.com/svn/trunk@1571 78cadc50-ecff-11dd-a971-7dbc132099af
xcode tests: Update exit codes for Xcode 4.

Fixes gyptest-ldflags-passed-to-libtool.py. Change other tests checking
the exit code for consistency.

BUG=chromium:175867
Review URL: https://codereview.chromium.org/12221160/

git-svn-id: http://gyp.googlecode.com/svn/trunk@1572 78cadc50-ecff-11dd-a971-7dbc132099af