[clang-tidy] new google-default-arguments check

Summary:
To check the google style guide rule here:
https://google.github.io/styleguide/cppguide.html#Default_Arguments

Patch by Clement Courbet!

Reviewers: hokein

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D19534

llvm-svn: 268919