[llvm] [mlir] [ADT] Reduce boilerplate in DenseSet (NFC) (PR #158456)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lldb-x86_64-debian` running on `lldb-x86_64-debian` while building `llvm` at step 6 "test".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/162/builds/31069

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

```
Step 6 (test) failure: build (failure)
...
UNSUPPORTED: lldb-api :: functionalities/tsan/thread_leak/TestTsanThreadLeak.py (878 of 3191)
PASS: lldb-api :: lang/cpp/static_member_type_depending_on_parent_size/TestStaticMemberTypeDependingOnParentSize.py (879 of 3191)
PASS: lldb-api :: linux/aarch64/sme_core_file/TestAArch64LinuxSMECoreFile.py (880 of 3191)
UNSUPPORTED: lldb-api :: functionalities/tty/TestTerminal.py (881 of 3191)
PASS: lldb-api :: functionalities/breakpoint/breakpoint_with_realpath_and_source_map/TestBreakpoint.py (882 of 3191)
PASS: lldb-shell :: Settings/TestFrameFormatFunctionTemplateArguments.test (883 of 3191)
UNSUPPORTED: lldb-api :: functionalities/asan/TestReportData.py (884 of 3191)
PASS: lldb-api :: linux/aarch64/non_address_bit_memory_access/TestAArch64LinuxNonAddressBitMemoryAccess.py (885 of 3191)
PASS: lldb-api :: test_utils/base/TestBaseTest.py (886 of 3191)
UNRESOLVED: lldb-api :: functionalities/postmortem/netbsd-core/TestNetBSDCore.py (887 of 3191)
******************** TEST 'lldb-api :: functionalities/postmortem/netbsd-core/TestNetBSDCore.py' FAILED ********************
Script:
--
/usr/bin/python3 /home/worker/2.0.1/lldb-x86_64-debian/llvm-project/lldb/test/API/dotest.py -u CXXFLAGS -u CFLAGS --env LLVM_LIBS_DIR=/home/worker/2.0.1/lldb-x86_64-debian/build/./lib --env LLVM_INCLUDE_DIR=/home/worker/2.0.1/lldb-x86_64-debian/build/include --env LLVM_TOOLS_DIR=/home/worker/2.0.1/lldb-x86_64-debian/build/./bin --arch x86_64 --build-dir /home/worker/2.0.1/lldb-x86_64-debian/build/lldb-test-build.noindex --lldb-module-cache-dir /home/worker/2.0.1/lldb-x86_64-debian/build/lldb-test-build.noindex/module-cache-lldb/lldb-api --clang-module-cache-dir /home/worker/2.0.1/lldb-x86_64-debian/build/lldb-test-build.noindex/module-cache-clang/lldb-api --executable /home/worker/2.0.1/lldb-x86_64-debian/build/./bin/lldb --compiler /home/worker/2.0.1/lldb-x86_64-debian/build/./bin/clang --dsymutil /home/worker/2.0.1/lldb-x86_64-debian/build/./bin/dsymutil --make /usr/bin/gmake --llvm-tools-dir /home/worker/2.0.1/lldb-x86_64-debian/build/./bin --lldb-obj-root /home/worker/2.0.1/lldb-x86_64-debian/build/tools/lldb --lldb-libs-dir /home/worker/2.0.1/lldb-x86_64-debian/build/./lib --cmake-build-type Release -t /home/worker/2.0.1/lldb-x86_64-debian/llvm-project/lldb/test/API/functionalities/postmortem/netbsd-core -p TestNetBSDCore.py
--
Exit Code: -11

Command Output (stdout):
--
lldb version 22.0.0git (https://github.com/llvm/llvm-project.git revision 3f26f1aed07f9671891b64594d9a7bd7c3df1f7c)
  clang revision 3f26f1aed07f9671891b64594d9a7bd7c3df1f7c
  llvm revision 3f26f1aed07f9671891b64594d9a7bd7c3df1f7c
Skipping the following test categories: ['libc++', 'msvcstl', 'dsym', 'gmodules', 'debugserver', 'objc']

--
Command Output (stderr):
--
Change dir to: /home/worker/2.0.1/lldb-x86_64-debian/llvm-project/lldb/test/API/functionalities/postmortem/netbsd-core
runCmd: settings clear --all

output: 

runCmd: settings set symbols.enable-external-lookup false

output: 

runCmd: settings set target.inherit-tcc true

output: 

runCmd: settings set target.disable-aslr false

output: 

runCmd: settings set target.detach-on-error false

output: 

runCmd: settings set target.auto-apply-fixits false

```

</details>

https://github.com/llvm/llvm-project/pull/158456