RFR: 8266962: Add arch supporting check for "Op_VectorLoadConst" before creating the node

[Nils Eliasson]

On Fri, 14 May 2021 06:04:45 GMT, Xiaohong Gong <xgong at openjdk.org> wrote:

> When creating the vector shuffle, the `"VectorLoadConstNode"` will be created to get an initial index vector. Before creating it, the compiler should check whether the current platform supports this opcode in case the jvm crashes with `"bad ad file"`. The compiler should finish the intrinsification and go back to the default java implementation if the backend doesn't support it.
> 
> Tested tier1 and jdk::tier3.

Looks good.

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Marked as reviewed by neliasso (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/4023