[llvm] [LTO] Compare std::optional<ImportKind> directly with ImportKind (NFC) (PR #105561)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-x86_64-debian-dylib` running on `gribozavr4` while building `llvm` at step 7 "test-build-unified-tree-check-llvm".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/60/builds/5591

Here is the relevant piece of the build log for the reference:
```
Step 7 (test-build-unified-tree-check-llvm) failure: test (failure)
******************** TEST 'LLVM :: ExecutionEngine/OrcLazy/multiple-compile-threads-basic.ll' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
RUN: at line 1: /b/1/llvm-x86_64-debian-dylib/build/bin/lli -jit-kind=orc-lazy -compile-threads=2 -thread-entry hello /b/1/llvm-x86_64-debian-dylib/llvm-project/llvm/test/ExecutionEngine/OrcLazy/multiple-compile-threads-basic.ll | /b/1/llvm-x86_64-debian-dylib/build/bin/FileCheck /b/1/llvm-x86_64-debian-dylib/llvm-project/llvm/test/ExecutionEngine/OrcLazy/multiple-compile-threads-basic.ll
+ /b/1/llvm-x86_64-debian-dylib/build/bin/lli -jit-kind=orc-lazy -compile-threads=2 -thread-entry hello /b/1/llvm-x86_64-debian-dylib/llvm-project/llvm/test/ExecutionEngine/OrcLazy/multiple-compile-threads-basic.ll
+ /b/1/llvm-x86_64-debian-dylib/build/bin/FileCheck /b/1/llvm-x86_64-debian-dylib/llvm-project/llvm/test/ExecutionEngine/OrcLazy/multiple-compile-threads-basic.ll
JIT session error: Resource tracker 0x12919c0 became defunct
lli: /b/1/llvm-x86_64-debian-dylib/llvm-project/llvm/include/llvm/ExecutionEngine/Orc/SymbolStringPool.h:282: llvm::orc::SymbolStringPool::~SymbolStringPool(): Assertion `Pool.empty() && "Dangling references at pool destruction time"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /b/1/llvm-x86_64-debian-dylib/build/bin/lli -jit-kind=orc-lazy -compile-threads=2 -thread-entry hello /b/1/llvm-x86_64-debian-dylib/llvm-project/llvm/test/ExecutionEngine/OrcLazy/multiple-compile-threads-basic.ll
 #0 0x00007f43aaa554a7 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/b/1/llvm-x86_64-debian-dylib/build/lib/libLLVM.so.20.0git+0xeae4a7)
 #1 0x00007f43aaa52f6e llvm::sys::RunSignalHandlers() (/b/1/llvm-x86_64-debian-dylib/build/lib/libLLVM.so.20.0git+0xeabf6e)
 #2 0x00007f43aaa55b7f SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f43a9b91140 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x13140)
 #4 0x00007f43a96b7ce1 raise (/lib/x86_64-linux-gnu/libc.so.6+0x38ce1)
 #5 0x00007f43a96a1537 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22537)
 #6 0x00007f43a96a140f (/lib/x86_64-linux-gnu/libc.so.6+0x2240f)
 #7 0x00007f43a96b0662 (/lib/x86_64-linux-gnu/libc.so.6+0x31662)
 #8 0x000000000042094c (/b/1/llvm-x86_64-debian-dylib/build/bin/lli+0x42094c)
 #9 0x00007f43ad1254e7 llvm::orc::ExecutorProcessControl::~ExecutorProcessControl() (/b/1/llvm-x86_64-debian-dylib/build/lib/libLLVM.so.20.0git+0x357e4e7)
#10 0x00007f43ad127142 llvm::orc::SelfExecutorProcessControl::~SelfExecutorProcessControl() crtstuff.c:0:0
#11 0x00007f43ad02bad1 llvm::orc::ExecutionSession::~ExecutionSession() (/b/1/llvm-x86_64-debian-dylib/build/lib/libLLVM.so.20.0git+0x3484ad1)
#12 0x00007f43ad0a80bd llvm::orc::LLJIT::~LLJIT() (/b/1/llvm-x86_64-debian-dylib/build/lib/libLLVM.so.20.0git+0x35010bd)
#13 0x00007f43ad0ad064 llvm::orc::LLLazyJIT::~LLLazyJIT() crtstuff.c:0:0
#14 0x0000000000415ba6 runOrcJIT(char const*) (/b/1/llvm-x86_64-debian-dylib/build/bin/lli+0x415ba6)
#15 0x000000000040fe49 main (/b/1/llvm-x86_64-debian-dylib/build/bin/lli+0x40fe49)
#16 0x00007f43a96a2d0a __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x23d0a)
#17 0x000000000040e9aa _start (/b/1/llvm-x86_64-debian-dylib/build/bin/lli+0x40e9aa)
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /b/1/llvm-x86_64-debian-dylib/build/bin/FileCheck /b/1/llvm-x86_64-debian-dylib/llvm-project/llvm/test/ExecutionEngine/OrcLazy/multiple-compile-threads-basic.ll

--

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


```

https://github.com/llvm/llvm-project/pull/105561