RFR: 8278125: Some preallocated OOMEs are missing stack trace

[Yi Yang]

Our customer found that the PreallocatedOutOfMemoryErrorCount is 4 by default. It ought to pre-allocate 4 OOMEs with stack trace, but in fact, no matter how many OOMEs are thrown, only 2 OOMEs have proper stack trace. This is because PreallocatedOutOfMemoryErrorCount is consumed multiple times:

VM tries to allocate a huge object while Java heap is insufficient to accommodate, it goes to:

https://github.com/openjdk/jdk/blob/b79554bb5cef14590d427543a40efbcc60c66548/src/hotspot/share/gc/shared/memAllocator.cpp#L115-L136

Line 135(`Universe::out_of_memory_error_java_heap`->`Universe::gen_out_of_memory_error`) and line 136(`THROW_OOP_`->`Exceptions::_throw`->`Exceptions::count_out_of_memory_exceptions`->`Universe::out_of_memory_error_java_heap`->`Universe::gen_out_of_memory_error`) call `Universe::gen_out_of_memory_error` twice in a single OOM event, which leads this unexpected scenario. Proposed fix is to remove such call in `Exceptions::count_out_of_memory_exceptions`.

Thanks.

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Commit messages:
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 - 8278125 Some preallocated OOMEs are missing stack trace

Changes: https://git.openjdk.java.net/jdk/pull/6672/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6672&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8278125
  Stats: 64 lines in 2 files changed: 62 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6672.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6672/head:pull/6672

PR: https://git.openjdk.java.net/jdk/pull/6672