[ARM64] [Windows] Improve error reporting for unsupported SEH unwind.

Use report_fatal_error instead of crashing or miscompiling. (It's
currently easier than it should be to hit this case because we don't
reuse codes across epilogs.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346440 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed