[NativeProcessLinux] Bugfix in the monitor thread
[NativeProcessLinux] Bugfix in the monitor thread

Make sure we dont treat EINTR as a fatal error. I was getting this when trying to profile the
debugger. I'm not sure why this wasn't surfacing before, it could be that the profiler is using
some signals internally.

git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@242681 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb