TableGen: add some more helpful error messages

Summary: Change-Id: I6f3dacf675a4126134577616e259696bebdade3a

Reviewers: tra, simon_tatham, craig.topper, MartinO, arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D47429

Change-Id: I614de12a4c154c6d53c090f2f3e53ad2d09942c5

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333436 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed