RFR: 8285007: Use correct lookup mode for MethodHandleStatics.UNSAFE

[Mandy Chung]

On Tue, 19 Apr 2022 13:19:31 GMT, Claes Redestad <redestad at openjdk.org> wrote:

> Trivially fix the resolution of the `NF_UNSAFE` named function to use the appropriate lookup mode.
> 
> In [JDK-8187826](https://bugs.openjdk.java.net/browse/JDK-8187826) we changed from regular reflection to use a `NamedFunction` for this field, but it appears the lookup mode came out wrong. This mismatch appears to be benign and ignored by HotSpot, but a user implementing an experimental JVM ran into some issues (and additionally noticed the resolve throws the wrong exception). 
> 
> This patch is a point fix to this particular issue, but I think we should consider following up with a stronger assertion or test for proper staticness of fields somewhere when resolving fields via `MemberName.getFactory().resolveOrNull(..)`.

src/java.base/share/classes/java/lang/invoke/DirectMethodHandle.java line 901:

> 899:                     MemberName member = new MemberName(MethodHandleStatics.class, "UNSAFE", Unsafe.class, REF_getStatic);
> 900:                     return new NamedFunction(
> 901:                             MemberName.getFactory().resolveOrFail(REF_getField, member,

`REF_getField` passed to `resolveOrFail` should also be corrected?

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PR: https://git.openjdk.java.net/jdk/pull/8297