IR: Remove unnecessary fields from MDTemplateParameter

I noticed this fields were never used in r228607, but I neglected to
propagate that into `MDTemplateParameter` until now.  This really should
have been done before commit in r228640; sorry for the churn.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228652 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed