gc/CriticalNativeArgs.java fails without -XX:-CriticalJNINatives

Found this with Zero testing, but the failure is not Zero-specific. It affects platforms that do not have CriticalJNINatives enabled. The issue is that the fallback (non-critical) version of the code calls GetArrayLength on known NULL array.

$ CONF=linux-x86_64-zero-fastdebug make exploded-test TEST=gc/CriticalNativeArgs.java
#
# Internal Error (/home/shade/trunks/jdk/src/hotspot/share/runtime/jniHandles.inline.hpp:91), pid=1909139, tid=1909217
# assert(handle != __null) failed: JNI handle should not be null

It was exposed by JDK-8233343 that added the generic test configuration. Before that, the test was only enabled for specific GCs and arches where CriticalJNINatives are known to work.