[llvm] [ThinLTO] Simplify checking for single external copy (NFCI) (PR #164861)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-sve-vls-2stage` running on `linaro-g3-03` while building `llvm` at step 12 "ninja check 2".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/4/builds/9973

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

```
Step 12 (ninja check 2) failure: stage 2 checked (failure)
******************** TEST 'ORC-aarch64-linux :: TestCases/Linux/aarch64/trivial-static-initializer.S' FAILED ********************
Exit Code: 139

Command Output (stderr):
--
/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   -c -o /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/orc/AARCH64LinuxConfig/TestCases/Linux/aarch64/Output/trivial-static-initializer.S.tmp /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/llvm/compiler-rt/test/orc/TestCases/Linux/aarch64/trivial-static-initializer.S # RUN: at line 7
+ /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -c -o /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/orc/AARCH64LinuxConfig/TestCases/Linux/aarch64/Output/trivial-static-initializer.S.tmp /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/llvm/compiler-rt/test/orc/TestCases/Linux/aarch64/trivial-static-initializer.S
/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./bin/llvm-jitlink -orc-runtime=/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./lib/../lib/clang/22/lib/aarch64-unknown-linux-gnu/liborc_rt.a /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/orc/AARCH64LinuxConfig/TestCases/Linux/aarch64/Output/trivial-static-initializer.S.tmp # RUN: at line 8
+ /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./bin/llvm-jitlink -orc-runtime=/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./lib/../lib/clang/22/lib/aarch64-unknown-linux-gnu/liborc_rt.a /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/orc/AARCH64LinuxConfig/TestCases/Linux/aarch64/Output/trivial-static-initializer.S.tmp
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
#0 0x0000ad9be786e650 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./bin/llvm-jitlink+0x2aae650)
#1 0x0000ad9be786c0d4 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./bin/llvm-jitlink+0x2aac0d4)
#2 0x0000ad9be786f3ec SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#3 0x0000e007d2b1e968 (linux-vdso.so.1+0x968)
#4 0x0000ad9be766d1f4 llvm::orc::AsynchronousSymbolQuery::handleComplete(llvm::orc::ExecutionSession&)::RunQueryCompleteTask::run() Core.cpp:0:0
#5 0x0000ad9be7746b1c std::thread::_State_impl<std::thread::_Invoker<std::tuple<llvm::orc::DynamicThreadPoolTaskDispatcher::dispatch(std::unique_ptr<llvm::orc::Task, std::default_delete<llvm::orc::Task>>)::$_0>>>::_M_run() TaskDispatch.cpp:0:0
#6 0x0000e007d28b29cc (/lib/aarch64-linux-gnu/libstdc++.so.6+0xd29cc)
#7 0x0000e007d2680398 start_thread ./nptl/pthread_create.c:442:8
#8 0x0000e007d26e9e9c ./misc/../sysdeps/unix/sysv/linux/aarch64/clone.S:82:0
/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/orc/AARCH64LinuxConfig/TestCases/Linux/aarch64/Output/trivial-static-initializer.S.script: line 2: 407027 Segmentation fault      /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./bin/llvm-jitlink -orc-runtime=/home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/./lib/../lib/clang/22/lib/aarch64-unknown-linux-gnu/liborc_rt.a /home/tcwg-buildbot/worker/clang-aarch64-sve-vls-2stage/stage2/runtimes/runtimes-bins/compiler-rt/test/orc/AARCH64LinuxConfig/TestCases/Linux/aarch64/Output/trivial-static-initializer.S.tmp

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/164861