Summary:
InferClang knows what to do if its name ends in ++. So it is not
necessary to pass whether or not the original clang executable ended in
++ to InferClang using the the INFER_XX environment variable. Instead,
create an InferClang++ symbolic link and make the clang wrapper call
either InferClang or InferClang++ as needed.
Reviewed By: jvillard
Differential Revision: D4078416
fbshipit-source-id: 3b5d5d0