C2's unaryOp vector intrinsic does not properly handle LongVector.neg

Executing jdk/incubator/vector/* with -XX:+UnlockExperimentalVMOptions -XX:PerMethodSpecTrapLimit=0 -XX:PerMethodTrapLimit=0 triggers:

# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/oracle/jdk/open/src/hotspot/share/prims/vectorSupport.cpp:297), pid=496845, tid=496853
# fatal error: NEG: long

Current CompileTask:
C2: 21564 1175 % b Long128VectorTests::NEGLong128VectorTests @ 50 (115 bytes)

Stack: [0x00007f1c1e037000,0x00007f1c1e138000], sp=0x00007f1c1e132840, free space=1006k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x191d4d5] VectorSupport::vop2ideal(int, BasicType)+0x6b5
V [libjvm.so+0x190df41] LibraryCallKit::inline_vector_nary_operation(int)+0x7d1
V [libjvm.so+0x12750e2] LibraryIntrinsic::generate(JVMState*)+0x302
V [libjvm.so+0x8262d0] CallGenerator::do_late_inline_helper()+0xab0
V [libjvm.so+0x9fea4d] Compile::inline_incrementally_one()+0x33d
V [libjvm.so+0x9fedaf] Compile::inline_incrementally(PhaseIterGVN&)+0x18f
V [libjvm.so+0x9ffa09] Compile::Optimize()+0x5e9
V [libjvm.so+0xa026ae] Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, bool, DirectiveSet*)+0x159e
V [libjvm.so+0x81d2b6] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x646
V [libjvm.so+0xa12ae9] CompileBroker::invoke_compiler_on_method(CompileTask*)+0xd09
V [libjvm.so+0xa13788] CompileBroker::compiler_thread_loop()+0x518
V [libjvm.so+0x1887f5c] JavaThread::thread_main_inner()+0x27c
V [libjvm.so+0x188e510] Thread::call_run()+0x100
V [libjvm.so+0x156de34] thread_native_entry(Thread*)+0x104