[NaryReassociate] Improve test CHECK

Add `CHECK` directives for the function calls.

Differential Revision: http://reviews.llvm.org/D12885

Patch by: Volkan Keles <vkeles@apple.com>

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247774 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed