RFR: JDK-8319104: GtestWrapper crashes with SIGILL in AsyncLogTest::test_asynclog_raw on AIX opt [v2]

[Joachim Kern]

> Currently gtest/GTestWrapper.java crashes on AIX in the opt build.
> 
>  SIGILL (0x4) at pc=0x0000000000000000, pid=15598006, tid=258
> 
>  JRE version: OpenJDK Runtime Environment (22.0) (build 22-internal-adhoc.openjdk.jdk-dev)
>  Java VM: OpenJDK 64-Bit Server VM (22-internal-adhoc.openjdk.jdk-dev, mixed mode, tiered, compressed oops, compressed class ptrs, g1 gc, aix-ppc64)
>  Problematic frame:
>  V [libjvm.so+0x42c9c] LogTagSet::vwrite(LogLevel::type, char const*, char*)+0x104
> 
> ### The reason for the SIGILL is the following:
> The _AsyncLogTest.asynclog_vm_ test iterates over the previously registered entries of _LogOutputList_. There it gets a Nullpointer, which it tries to use for a function call `(nullpointer)->write(...);` This results in an SIGILL.
> The first reason for this is, that the LogTagSet tests (which seem to be called beforehand only on AIX) creates such an entry with
> `ts.set_output_level(LogConfiguration::StdoutLog, LogLevel::Info);`
> The first flaw is that this entry is not removed again at the end of the test. So the VM is modified and would behave differently depending on the sequence of the test execution.
> The second flaw is that the registered _LogConfiguration::StdoutLog_ in the call above is still a nullpointer due to the fact that on AIX no VM was created before the LogTagSet tests and only a creation of a VM initializes the logConfiguration. So again the whole Gtestwrapper testsuite depends on the executable sequence of the tests. If no other test creates a vm beforehand the LogTagSet tests will fail. Again this has to be fixed by let the LogTagSet tests themself creating a VM.
> 
> ### Solution to fix all errors:
> 
> 1. Make the 1. LogTagSet test a TEST_VM test.
> 2. Clean up the _LogTagSet.is_level_ and _LogTagSet.level_for_ tests with a final `ts.set_output_level(LogConfiguration::StdoutLog, LogLevel::Off);` which will remove the entry from the LogOutputList again.

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

  make all tests of logTagSet VM tests

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16479/files
  - new: https://git.openjdk.org/jdk/pull/16479/files/8c6fcbca..10836b4b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16479&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16479&range=00-01

  Stats: 7 lines in 1 file changed: 0 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/16479.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16479/head:pull/16479

PR: https://git.openjdk.org/jdk/pull/16479