[llvm] r226248 - Use report_fatal_error instead of llvm_unreachable, so we don't crash on user input

[Rafael Espíndola]

> Added: llvm/trunk/test/Bitcode/invalid.test
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/invalid.test?rev=226248&view=auto
> ==============================================================================
> --- llvm/trunk/test/Bitcode/invalid.test (added)
> +++ llvm/trunk/test/Bitcode/invalid.test Thu Jan 15 22:54:12 2015
> @@ -0,0 +1 @@
> +RUN: not llvm-dis -disable-output %p/Inputs/invalid-pr20485.bc

FileCheck for the message?

Cheers,
Rafael