Add xcode_ninja_target_pattern to xcode-ninja generator
Add xcode_ninja_target_pattern to xcode-ninja generator

Adds new GYP_GENERATOR_FLAG xcode_ninja_target_pattern. This
customization allows for non-executable targets in the xcode_ninja wrapper.

Also changes the name of xcode_ninja_target_filter to
xcode_ninja_executable_target_pattern.

xcode_ninja_executable_target_pattern (default all)
  - Restrict executable targets to this pattern, if set.
xcode_ninja_target_pattern (default none)
  - Include extra targets, such as non-executable targets based on this pattern, if set.

BUG=None
TEST=None
R=mark@chromium.org

Review URL: https://codereview.chromium.org/234843005
old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google