[jdk20] RFR: 8298400: Virtual thread instability when stack overflows

[Ron Pressler]

The stack overflow is detected in the native code and a pending exception is set, but it is not thrown.

Additionally, the stack overflow detection is changed use StackOverflow::shadow_zone_safe_limit rather than StackOverflow::stack_overflow_limit.

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Commit messages:
 - Use StackOverflow::shadow_zone_safe_limit rather than StackOverflow::stack_overflow_limit in stack overflow tests in continuationFreezeThaw.cpp
 - Throw pending exception

Changes: https://git.openjdk.org/jdk20/pull/101/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk20&pr=101&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298400
  Stats: 22 lines in 3 files changed: 20 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk20/pull/101.diff
  Fetch: git fetch https://git.openjdk.org/jdk20 pull/101/head:pull/101

PR: https://git.openjdk.org/jdk20/pull/101