[jdk19] RFR: 8288759: GCC 12 fails to compile signature.cpp due to -Wstringop-overread [v2]

[Aleksey Shipilev]

> Trying to compile with GCC 12.1.1 (current Fedora Rawhide) yields this failure:
> 
> 
> In file included from /home/test/shipilev-jdk/src/hotspot/share/utilities/globalDefinitions_gcc.hpp:35,
>                  from /home/test/shipilev-jdk/src/hotspot/share/utilities/globalDefinitions.hpp:35,
>                  from /home/test/shipilev-jdk/src/hotspot/share/memory/allocation.hpp:29,
>                  from /home/test/shipilev-jdk/src/hotspot/share/classfile/classLoaderData.hpp:28,
>                  from /home/test/shipilev-jdk/src/hotspot/share/precompiled/precompiled.hpp:34:
> In function 'const void* memchr(const void*, int, size_t)',
>     inlined from 'int SignatureStream::scan_type(BasicType)' at /home/test/shipilev-jdk/src/hotspot/share/runtime/signature.cpp:343:32,
>     inlined from 'void SignatureStream::next()' at /home/test/shipilev-jdk/src/hotspot/share/runtime/signature.cpp:373:19,
>     inlined from 'void SignatureIterator::do_parameters_on(T*) [with T = Fingerprinter]' at /home/test/shipilev-jdk/src/hotspot/share/runtime/signature.hpp:635:41,
>     inlined from 'void SignatureIterator::do_parameters_on(T*) [with T = Fingerprinter]' at /home/test/shipilev-jdk/src/hotspot/share/runtime/signature.hpp:629:6,
>     inlined from 'void Fingerprinter::compute_fingerprint_and_return_type(bool)' at /home/test/shipilev-jdk/src/hotspot/share/runtime/signature.cpp:169:19:

Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Better fix the actual warning
 - Merge branch 'master' into JDK-8288759-gcc12-string-overread
 - Fix

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

Changes:
  - all: https://git.openjdk.org/jdk19/pull/49/files
  - new: https://git.openjdk.org/jdk19/pull/49/files/e74cede8..8209c0aa

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk19&pr=49&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk19&pr=49&range=00-01

  Stats: 2768 lines in 119 files changed: 2065 ins; 329 del; 374 mod
  Patch: https://git.openjdk.org/jdk19/pull/49.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/49/head:pull/49

PR: https://git.openjdk.org/jdk19/pull/49