AMDGPU/SI: Re add VIInstructions.td to unbreak bots

This file is unused as of r285939, but we need to keep it around
for bots that don't do full rebuilds.   We should be able to delete this
again in a few days.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285948 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed