RFR: 8294924: JvmtiExport::post_exception_throw() doesn't deal well with concurrent stack processing

[Erik Österlund]

On Fri, 18 Nov 2022 12:30:19 GMT, Erik Österlund <eosterlund at openjdk.org> wrote:

> There is a stack walk in JvmtiExport::post_exception_throw() that has safepoints in it. This trips up the stack watermark code. This patch adds a RAII object to JvmtiExport::post_exception_throw() that keeps the thread and its stack fully processed throughout the function.
> Testing: tier1-7 of ZGC tests on linux x86_64 debug and manual testing of the test that failed.

Thanks for the reviews, @dholmes-ora, @pchilano and @sspitsyn! I added a comment as requested.

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PR: https://git.openjdk.org/jdk/pull/11238