[compiler-rt] [libfuzzer] use timer_create() instead of setitimer() for linux (PR #110274)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `compiler-rt` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/8274

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
...
0.034 [2/6/4] Building CXX object compiler-rt/lib/memprof/CMakeFiles/RTMemprof_dynamic_version_script_dummy.x86_64.dir/dummy.cpp.o
0.034 [1/6/5] Building CXX object compiler-rt/lib/nsan/CMakeFiles/RTNsan_dynamic_version_script_dummy.x86_64.dir/dummy.cpp.o
0.078 [0/6/6] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/20/lib/x86_64-unknown-linux-gnu/libclang_rt.ubsan_standalone.so
0.080 [0/5/7] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/20/lib/x86_64-unknown-linux-gnu/libclang_rt.nsan.so
0.086 [0/4/8] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/20/lib/x86_64-unknown-linux-gnu/libclang_rt.hwasan_aliases.so
0.091 [0/3/9] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/20/lib/x86_64-unknown-linux-gnu/libclang_rt.hwasan.so
0.093 [0/2/10] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/20/lib/x86_64-unknown-linux-gnu/libclang_rt.memprof.so
0.103 [0/1/11] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/20/lib/x86_64-unknown-linux-gnu/libclang_rt.asan.so
1.814 [3/1/14] cd /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins && /usr/bin/cmake/bin/cmake --build /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/ --target runtimes-test-depends --config Release
0.382 [0/2/1] Generating Fuzzer-x86_64-Test
FAILED: compiler-rt/lib/fuzzer/tests/Fuzzer-x86_64-Test /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/lib/fuzzer/tests/Fuzzer-x86_64-Test 
cd /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/lib/fuzzer/tests && /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang++ FuzzerTestObjects.FuzzerUnittest.cpp.x86_64.o FuzzerTestObjects.gtest-all.cc.x86_64.o /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/lib/fuzzer/tests/libRTFuzzerTest.x86_64.a -o /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/lib/fuzzer/tests/./Fuzzer-x86_64-Test -fuse-ld=gold -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -resource-dir=/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./lib/../lib/clang/20 --driver-mode=g++ -lpthread -m64
/usr/bin/ld.gold: internal error in read_header_prolog, at ../../gold/dwarf_reader.cc:1678
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
9.513 [0/1/2] Checking TSan Go runtime...
ninja: build stopped: subcommand failed.
FAILED: runtimes/CMakeFiles/runtimes-test-depends /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/CMakeFiles/runtimes-test-depends 
cd /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins && /usr/bin/cmake/bin/cmake --build /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/ --target runtimes-test-depends --config Release
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/110274