[CodeGen] Add a -trap-unreachable option for debugging

Add a common -trap-unreachable option, similar to the target
specific hexagon equivalent, which has been replaced. This
turns unreachable instructions into traps, which is useful for
debugging.

Differential Revision: https://reviews.llvm.org/D42965



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324880 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed