Summary:
This teaches clang how to parse and lower the 'interrupt' and 'naked'
attributes.
This allows interrupt signal handlers to be written.
Reviewers: aaron.ballman
Subscribers: malcolm.parsons, cfe-commits
Differential Revision: https://reviews.llvm.org/D28451
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@294402 91177308-0d34-0410-b5e6-96231b3b80d8
Dylan McKay