Populate list of vectorizable functions for Accelerate library.

Populate list of vectorizable functions for Accelerate library.

Summary:
This patch adds majority of supported by Accelerate library functions to the
list of vectorizable functions.

The full list of available vector functions could be found here:
https://developer.apple.com/library/mac/documentation/Performance/Conceptual/vecLib/index.html

Test Plan: Unit tests are added.

Reviewers: hfinkel, aschwaighofer, nadav

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9543

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236747 91177308-0d34-0410-b5e6-96231b3b80d8