TableGen: add !isa operation

Change-Id: Iddb724c3ae706d82933a2d82c91d07e0e36b30e3

Differential revision: https://reviews.llvm.org/D44105

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327117 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed