[PATCH] cpp11-migrate: Add '-supports' command line switch.

[Sean Silva]

  > How about just `-for-compiler`. I'm in favour of a comma-separated list.

  I like this. Maybe `-for-compilers` plural since AFAIK most projects support more than one compiler (it also makes it more obvious that it takes a comma separated list).

http://llvm-reviews.chandlerc.com/D1202

BRANCH
  supports-cmd-2

ARCANIST PROJECT
  clang-tools-extra