RFR: 8320139: [JVMCI] VmObjectAlloc is not generated by intrinsics methods which allocate objects [v2]

[Raphael Mosaner]

> This PR exports a pointer to `JvmtiExport::_should_notify_object_alloc` via JVMCI to enable intrinsification of unsafe allocations in accordance to C2.

Raphael Mosaner has updated the pull request incrementally with one additional commit since the last revision:

  [JVMCI] Documentation for _should_notify_object_alloc export.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/16980/files
  - new: https://git.openjdk.org/jdk/pull/16980/files/0b430d8b..35b2fd9c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16980&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16980&range=00-01

  Stats: 5 lines in 1 file changed: 5 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16980.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16980/head:pull/16980

PR: https://git.openjdk.org/jdk/pull/16980