[jdk11u-dev] RFR: 8315380: AsyncGetCallTrace crash in frame::safe_for_sender

[Jaroslav Bachorik]

This change is fixing the problem in `frame_aarch64.cpp`, function `safe_for_sender`, where we have this code


bool unextended_sp_safe = unextended_sp < thread->stack_base();


While this captures one possibility of not being safe, it omits the check for `unextended_sp` falling within the stack space.

The proposed change then is


bool unextended_sp_safe = (unextended_sp < thread->stack_base() && \
                             sp >= thread->stack_base() - thread->stack_size());


This is actually just making sure the behaviour is the same as in JDK 15+ (since [JDK-8238988](https://bugs.openjdk.org/browse/JDK-8238988)) where the `unextended_sp` is checked for being within the stack limits.


The change is not accompanied by a JTReg test because I was not able to craft one triggering the issue reliably.

Existing tests from tier1-tier4 were run on a linux-aarch64 system with no new failures observed.

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Commit messages:
 - 8315380: AsyncGetCallTrace crash in frame::safe_for_sender

Changes: https://git.openjdk.org/jdk11u-dev/pull/3003/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=3003&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315380
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/3003.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/3003/head:pull/3003

PR: https://git.openjdk.org/jdk11u-dev/pull/3003