[NVPTX] Reformat NVPTXInstrInfo.td, and add additional comments.

Summary:
Also simplify some of the embedded C++ logic.

No functional changes.

Reviewers: jholewinski

Subscribers: llvm-commits, tra, jholewinski

Differential Revision: http://reviews.llvm.org/D17354

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262371 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed