Use LLVM_BUILTIN_TRAP instead of lame volatile int traps.

(from a todo mentioned in r159469 & originally suggested by Chandler Carruth)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162302 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed