Unlike on Unix, we can't fall back to an alternative implementation.
Failure to emit an early error would cause later native method calls to
produce a less informative error message.

See https://github.com/bazelbuild/bazel/issues/20677 for a recent
example where this would have been helpful.

Also note some minor changes:
* Since we attempt to load the JNI in two different ways, make sure to
propagate both exceptions (one suppressed by the other).
* The default switch case is unnecessary, as errorprone already enforces
exhaustiveness.

PiperOrigin-RevId: 595206761
Change-Id: I4b6258d59d9a4fcc9f83418375acc51a32d7f4a4