RFR: 8302518: Add missing Op_RoundDoubleMode in VectorNode::vector_operands() [v2]

[Jatin Bhateja]

On Mon, 20 Feb 2023 08:08:53 GMT, Pengfei Li <pli at openjdk.org> wrote:

>> This is a one-line fix.
>> 
>> `VectorNode::vector_operands()` is a C2 function used to get a half-open range of `[start, end)` defining which operands are vectors to process. `Op_RoundDoubleMode` has two operands but only the 1st one is a vector. Its 2nd operand is the rounding mode. Missing this op results in its 2nd operand treated as a vector. It is fortunate that it hasn't caused any issue yet as the code follows just treated the 2nd input as an immediate to replicate later. If we add some check like `n->is_Vector()` for the vectorized node then, there will be issues. We should fix this potential problem.
>> 
>> Tested tier1.
>
> Pengfei Li has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add rotate shift opcodes

Thanks @pfustc, LGTM.

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Marked as reviewed by jbhateja (Reviewer).

PR: https://git.openjdk.org/jdk/pull/12584