[llvm] [llvm] Use "= default" (NFC) (PR #166088)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-win-x-aarch64` running on `as-builder-2` while building `llvm` at step 14 "test-check-cxxabi-aarch64-unknown-linux-gnu".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/193/builds/11920

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 14 (test-check-cxxabi-aarch64-unknown-linux-gnu) failure: Test just built components: check-cxxabi-aarch64-unknown-linux-gnu completed (failure)
******************** TEST 'llvm-libc++abi-static.cfg.in :: itanium_demangle_matches_llvm.sh.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 4
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/ItaniumDemangle.h > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_demangle
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/ItaniumDemangle.h
# RUN: at line 5
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/ItaniumDemangle.h > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_demangle
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/ItaniumDemangle.h
# RUN: at line 6
diff C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_demangle C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_demangle
# executed command: diff 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_demangle' 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_demangle'
# RUN: at line 8
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/ItaniumNodes.def > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_nodes
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/ItaniumNodes.def
# RUN: at line 9
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/ItaniumNodes.def > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_nodes
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/ItaniumNodes.def
# RUN: at line 10
diff C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_nodes C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_nodes
# executed command: diff 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_nodes' 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_nodes'
# RUN: at line 12
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/StringViewExtras.h > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_extras
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/StringViewExtras.h
# RUN: at line 13
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/StringViewExtras.h > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_extras
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/StringViewExtras.h
# RUN: at line 14
diff C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_extras C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_extras
# executed command: diff 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_extras' 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_extras'
# RUN: at line 16
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/Utility.h > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_utility
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/libcxxabi/src/demangle/Utility.h
# RUN: at line 17
tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/Utility.h > C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_utility
# executed command: tail -n +3 C:/buildbot/as-builder-2/x-aarch64/llvm-project/runtimes/../llvm/include/llvm/Demangle/Utility.h
# RUN: at line 18
diff C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_utility C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_utility
# executed command: diff 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_utility' 'C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_utility'
# .---command stdout------------
# | *** C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.libcxxabi_utility
# | --- C:\buildbot\as-builder-2\x-aarch64\build\runtimes\runtimes-aarch64-unknown-linux-gnu-bins\libcxxabi\test\Output\itanium_demangle_matches_llvm.sh.test.dir\t.tmp.llvm_utility
# | ***************
# | *** 79,85 ****
# |     OutputBuffer(const OutputBuffer &) = delete;
# |     OutputBuffer &operator=(const OutputBuffer &) = delete;
# |   
# | !   virtual ~OutputBuffer() {}
...

```

</details>

https://github.com/llvm/llvm-project/pull/166088