test/jdk/jdk/incubator/vector/Byte256VectorTests.java fails on riscv with the following error:
```
test Byte256VectorTests.negByte256VectorTests (byte [i * 5]): failure
java.lang.AssertionError: at index #2, input = 10 expected [-10] but found [-11]
```

Currently, `NegVI` can only handle the vector element basic type `T_INT` with`vsetvli(t0, x0, Assembler::e32)` but `T_SHORT/T_BYTE` can also be matched with `NegVI`, so these two types of tests are currently failing:
`test/jdk/jdk/incubator/vector/Byte*VectorTests.java`
`test/jdk/jdk/incubator/vector/Short*VectorTests.java`