[llvm] [llvm] Remove redundant calls to std::unique_ptr<T>::get (NFC) (PR #97914)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `bolt-aarch64-ubuntu-clang` running on `bolt-worker-aarch64` while building `llvm` at step 5 "build-clang-bolt".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/128/builds/157

Here is the relevant piece of the build log for the reference:
```
Step 5 (build-clang-bolt) failure: build (failure)
...
BOLT-INFO: padding code to 0x15c00000 to accommodate hot text
BOLT-INFO: output linked against instrumentation runtime library, lib entry point is 0x187788d4
BOLT-INFO: clear procedure is 0x187774d0
BOLT-INFO: patched build-id (flipped last bit)
BOLT-INFO: setting __bolt_runtime_start to 0x18778840
BOLT-INFO: setting __bolt_runtime_fini to 0x187788d4
BOLT-INFO: setting __hot_start to 0x8a00000
BOLT-INFO: setting __hot_end to 0x15aa1d48
1046.418 [2/1/3004] Generating BOLT profile for Clang
-- Testing: 1 tests, 1 workers --
FAIL: Clang Perf Training :: cxx/hello_world.cpp (1 of 1)
******************** TEST 'Clang Perf Training :: cxx/hello_world.cpp' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/home/worker/buildbot-aarch64/bolt-aarch64-ubuntu-clang/build/bin/clang-bolt.inst --driver-mode=g++  -c /home/worker/buildbot-aarch64/llvm-project/clang/utils/perf-training/cxx/hello_world.cpp
# executed command: /home/worker/buildbot-aarch64/bolt-aarch64-ubuntu-clang/build/bin/clang-bolt.inst --driver-mode=g++ -c /home/worker/buildbot-aarch64/llvm-project/clang/utils/perf-training/cxx/hello_world.cpp
# .---command stderr------------
# | free(): invalid pointer
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
# | Stack dump:
# | 0.	Program arguments: /home/worker/buildbot-aarch64/bolt-aarch64-ubuntu-clang/build/bin/clang-bolt.inst --driver-mode=g++ -c /home/worker/buildbot-aarch64/llvm-project/clang/utils/perf-training/cxx/hello_world.cpp
# | 1.	<eof> parser at end of file
# | Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
# | 0  clang-bolt.inst 0x0000aaaadb12b5a0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 68
# | 1  clang-bolt.inst 0x0000aaaadb125a1c llvm::sys::RunSignalHandlers() + 156
# | 2  clang-bolt.inst 0x0000aaaadaf7710c
# | 3  linux-vdso.so.1 0x0000ffff943307dc __kernel_rt_sigreturn + 0
# | 4  libc.so.6       0x0000ffff93e8f200
# | 5  libc.so.6       0x0000ffff93e4a67c raise + 28
# | 6  libc.so.6       0x0000ffff93e37130 abort + 228
# | 7  libc.so.6       0x0000ffff93e83308
# | 8  libc.so.6       0x0000ffff93e9957c
# | 9  libc.so.6       0x0000ffff93e9b2c4
# | 10 libc.so.6       0x0000ffff93e9dc84 free + 176
# | 11 clang-bolt.inst 0x0000aaaada94e724 llvm::MCContext::~MCContext() + 4552
# | 12 clang-bolt.inst 0x0000aaaad932fccc
# | 13 clang-bolt.inst 0x0000aaaada3047c0 llvm::PMTopLevelManager::~PMTopLevelManager() + 432
# | 14 clang-bolt.inst 0x0000aaaada3051a0
# | 15 clang-bolt.inst 0x0000aaaada2f7c0c llvm::legacy::PassManager::~PassManager() + 132
# | 16 clang-bolt.inst 0x0000aaaadc44e8c0 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) + 9856
# | 17 clang-bolt.inst 0x0000aaaadc62d808 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) + 2884
# | 18 clang-bolt.inst 0x0000aaaae0eeeb98 clang::ParseAST(clang::Sema&, bool, bool) + 3200
# | 19 clang-bolt.inst 0x0000aaaadcf5f760 clang::FrontendAction::Execute() + 540
# | 20 clang-bolt.inst 0x0000aaaadce3ffb8 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 3128
# | 21 clang-bolt.inst 0x0000aaaadd155808 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 1400
# | 22 clang-bolt.inst 0x0000aaaad8013324 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) + 16268

```

https://github.com/llvm/llvm-project/pull/97914