[foreign] RFR: 8226457: Refactor duplicated code in universalNativeInvoker

[Nick Gasson]

Hi,

This is an attempt to remove some of the duplication we now have between 
the AArch64 and x86 versions of universalNativeInvoker. The classes 
ShuffleRecipe, ShuffleRecipeStream and ShuffleRecipeVerifier that were 
previously in universalNativeInvoker_{x86,aarch64}.cpp actually have no 
platform-specific code so can go in the shared 
universalNativeInvoker.[ch]pp.

Bug: https://bugs.openjdk.java.net/browse/JDK-8226457
Webrev: http://cr.openjdk.java.net/~ngasson/foreign/8226457/webrev.0/

Tested jtreg jdk_foreign on X86 and AArch64.

Thanks,
Nick