8347463: jdk/jfr/threading/TestManyVirtualThreads.java crashes with assert(oopDesc::is_oop_or_null(val))

[anton-seoane]

This PR introduces a fix for a intermittent assert crash due to a non-oop found in the stack when deoptimizing.

The inline_native_GetEventWriter JFR intrinsic performs a call into the runtime, which can safepoint, to write a checkpoint for the vthread. This call returns a global handle (jobject) that then gets resolved to a raw oop.

However, the corresponding jfr_write_checkpoint_Type does not set any return, modelling the call as void. If a safepoint hits in the small window after the stub returns but before the writer oop is used, and the GC moves the object in that window, the deoptimization path cannot resolve a handle that it never recorded, leading to the subsequent crash.

Testing: passes tiers 1-5

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Progress

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Issue

• JDK-8347463: jdk/jfr/threading/TestManyVirtualThreads.java crashes with assert(oopDesc::is_oop_or_null(val)) (Bug - P3)

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[openjdk]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (a6225ebd)

[robcasloz]

/cc hotspot-jfr

[openjdk]

@robcasloz
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[anton-seoane]

Switching back to draft after conversation with @robcasloz, to perform further investigation