There's no need for fatalError() to try to generate its own backtraces
when the runtime's backtracer is enabled. Not only is the code it uses
more fragile but it also doesn't support async or inline frames and it
can't look-up symbols properly either.
rdar://117470489
Turn on frame pointers for the Swift runtime libraries. This makes
backtraces that go through the runtimes more reliable without having
to parse DWARF data.
rdar://116112040
