RFR: 8333730: ubsan: FieldIndices/libFieldIndicesTest.cpp:276:11: runtime error: null pointer passed as argument 2, which is declared to never be null

[Matthias Baesken]

When running HS :tier1 tests with ubsan-enabled binaries, the following issue is reported :
test
serviceability/jvmti/FollowReferences/FieldIndices/FieldIndicesTest.jtr

test/hotspot/jtreg/serviceability/jvmti/FollowReferences/FieldIndices/libFieldIndicesTest.cpp:276:11: runtime error: null pointer passed as argument 2, which is declared to never be null
    #0 0x7efea442e379 in Klass::explore_interfaces(JNIEnv_*) test/hotspot/jtreg/serviceability/jvmti/FollowReferences/FieldIndices/libFieldIndicesTest.cpp:276
    #1 0x7efea443280d in Klass::explore(JNIEnv_*, _jclass*) test/hotspot/jtreg/serviceability/jvmti/FollowReferences/FieldIndices/libFieldIndicesTest.cpp:322
    #2 0x7efea4433adf in Object::explore(JNIEnv_*, _jobject*) test/hotspot/jtreg/serviceability/jvmti/FollowReferences/FieldIndices/libFieldIndicesTest.cpp:349
    #3 0x7efea443443b in Java_FieldIndicesTest_prepare test/hotspot/jtreg/serviceability/jvmti/FollowReferences/FieldIndices/libFieldIndicesTest.cpp:489
    #4 0x7efe7f8d1e7b (<unknown module>)

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Commit messages:
 - JDK-8333730

Changes: https://git.openjdk.org/jdk/pull/19657/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19657&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333730
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/19657.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19657/head:pull/19657

PR: https://git.openjdk.org/jdk/pull/19657