RFR: 8357188: Remove the field MemAllocator::Allocation::_overhead_limit_exceeded and the related code

[Guoxiong Li]

Hi all,

After JDK-8338977 [1], the field `MemAllocator::Allocation::_overhead_limit_exceeded` and the parameter `gc_overhead_limit_was_exceeded` of the method `CollectedHeap::mem_allocate` are not used by any GC. This patch removes them.

Test:
All the tests of the command `make test TEST="hotspot:hotspot_gc"` passed locally (linux, x86_64, release build).

Best Regards,
-- Guoxiong

[1] https://bugs.openjdk.org/browse/JDK-8338977

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Commit messages:
 - JDK-8357188

Changes: https://git.openjdk.org/jdk/pull/27020/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27020&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357188
  Stats: 38 lines in 14 files changed: 0 ins; 18 del; 20 mod
  Patch: https://git.openjdk.org/jdk/pull/27020.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27020/head:pull/27020

PR: https://git.openjdk.org/jdk/pull/27020