8267321: Use switch expression for VarHandle$AccessMode lookup

[cl4es]

Using a switch expression instead of a (read-only) static HashMap reduces initialization overhead of VarHandle$AccessMode. This gets loaded earlier after JDK-8265079, so it started showing up in a few lambda startup tests.

This also obsoletes a jtreg test that only verified that this map was optimally sized.

---

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Issue

• JDK-8267321: Use switch expression for VarHandle$AccessMode lookup

Reviewers

• Jorn Vernee (@JornVernee - Reviewer)

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[mlbridge]

Webrevs

• 00: Full (e5745dde)

[JornVernee]

LGTM. I assume existing tests verify that all values of the enum are covered by the switch?

[openjdk]

@cl4es This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8267321: Use switch expression for VarHandle$AccessMode lookup

Reviewed-by: jvernee

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At the time when this comment was updated there had been 30 new commits pushed to the master branch:

• fdd0352: 8267338: [JVMCI] revive JVMCI API removed by JDK-8243287
• 0b49f5a: 8267257: Shenandoah: Always deduplicate strings when it is enabled during full gc
• 12050f0: 8266651: Convert Table method parameters from String to Content
• e749f75: 8267304: Bump global JTReg memory limit to 768m
• e858dd6: 8267361: JavaTokenizer reads octal numbers mistakenly
• 1b93b81: 8267133: jdk/jfr/event/gc/collection/TestG1ParallelPhases.java fails with Not expected phases: RestorePreservedMarks, RemoveSelfForwardingPtr: expected true, was false
• 88b1142: 8267357: build breaks with -Werror option on micro benchmark added for JDK-8256973
• 6ef46ce: 8231672: Simplify the reference processing parallelization framework
• 392f962: 8267151: C2: Don't create dummy Opaque1Node for outmost unswitched IfNode
• 0cf7e57: 8267239: C1: RangeCheckElimination for % operator if divisor is IntConstant
• ... and 20 more: https://git.openjdk.java.net/jdk/compare/894547d2c102dcbe1f9ec8a1edb11c6b31e4270e...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[cl4es]

LGTM. I assume existing tests verify that all values of the enum are covered by the switch?

Thanks! Yes, the method with the switch is called when linking a VH, and the tests should be exhaustive in that regard.

[cl4es]

/integrate

[openjdk]

@cl4es Since your change was applied there have been 30 commits pushed to the master branch:

• fdd0352: 8267338: [JVMCI] revive JVMCI API removed by JDK-8243287
• 0b49f5a: 8267257: Shenandoah: Always deduplicate strings when it is enabled during full gc
• 12050f0: 8266651: Convert Table method parameters from String to Content
• e749f75: 8267304: Bump global JTReg memory limit to 768m
• e858dd6: 8267361: JavaTokenizer reads octal numbers mistakenly
• 1b93b81: 8267133: jdk/jfr/event/gc/collection/TestG1ParallelPhases.java fails with Not expected phases: RestorePreservedMarks, RemoveSelfForwardingPtr: expected true, was false
• 88b1142: 8267357: build breaks with -Werror option on micro benchmark added for JDK-8256973
• 6ef46ce: 8231672: Simplify the reference processing parallelization framework
• 392f962: 8267151: C2: Don't create dummy Opaque1Node for outmost unswitched IfNode
• 0cf7e57: 8267239: C1: RangeCheckElimination for % operator if divisor is IntConstant
• ... and 20 more: https://git.openjdk.java.net/jdk/compare/894547d2c102dcbe1f9ec8a1edb11c6b31e4270e...master

Your commit was automatically rebased without conflicts.

Pushed as commit 9760dba.

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