RFR: 8346193: CrashGCForDumpingJavaThread do not trigger expected crash build with clang17 [v6]

[SendaoYan]

> Hi all,
> Function `frame::oops_do_internal` in src/hotspot/share/runtime/frame.cpp assign value to a nullptr `char *t` and intended to cause jvm crash. But after the assignment the nullptr do not use anymore, so clang17 consider the `char *t` initialization and assignment is "dead code". This PR use function `guarantee` instead of 'write a byte to nullptr' to trigger the expected jvm crash, risk is low.
> 
> Here is the example explain the "dead code" elimination.
> 
> 1. Without volatile modifier, clang will delete the "dead code" and cause no more Segmentation fault error by -O1.
> 
> 
>> cat demo.c 
> int main() { char *t = 0; *t = 'c'; return 0; }
>> clang -O0 demo.c && ./a.out ; echo $?
> Segmentation fault (core dumped)
> 139
>> clang -O1 demo.c && ./a.out ; echo $?
> 0
> 
> 
> 2. With volatile modifier, clang do not delete the "dead code" again and and the expected Segmentation fault occur by -O1.
> 
>> cat demo.c 
> int main() { volatile char *t = 0; *t = 'c'; return 0; }
>> clang -O0 demo.c && ./a.out ; echo $?
> Segmentation fault (core dumped)
> 139
>> clang -O1 demo.c && ./a.out ; echo $?
> Segmentation fault (core dumped)
> 139

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

  Remove duplicate CrashGCForDumpingJavaThread check

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/22757/files
  - new: https://git.openjdk.org/jdk/pull/22757/files/f216aa6f..12242b2b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22757&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22757&range=04-05

  Stats: 2 lines in 1 file changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22757.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22757/head:pull/22757

PR: https://git.openjdk.org/jdk/pull/22757