[llvm] expand-fp: Refactor modification status handling (NFC) (PR #163542)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

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

Full details are available at: https://lab.llvm.org/buildbot/#/builders/144/builds/38187

<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)
******************** TEST 'lld :: ELF/linkerscript/empty-relaplt-dyntags.test' FAILED ********************
Exit Code: 250

Command Output (stdout):
--
# RUN: at line 2
/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/llvm-mc -filetype=obj -triple=x86_64-pc-linux /dev/null -o /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/lld/test/ELF/linkerscript/Output/empty-relaplt-dyntags.test.tmp.o
# executed command: /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/llvm-mc -filetype=obj -triple=x86_64-pc-linux /dev/null -o /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/lld/test/ELF/linkerscript/Output/empty-relaplt-dyntags.test.tmp.o
# note: command had no output on stdout or stderr
# RUN: at line 3
/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/ld.lld -shared /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/lld/test/ELF/linkerscript/Output/empty-relaplt-dyntags.test.tmp.o -T /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/lld/test/ELF/linkerscript/empty-relaplt-dyntags.test -o /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/lld/test/ELF/linkerscript/Output/empty-relaplt-dyntags.test.tmp
# executed command: /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/ld.lld -shared /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/lld/test/ELF/linkerscript/Output/empty-relaplt-dyntags.test.tmp.o -T /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/lld/test/ELF/linkerscript/empty-relaplt-dyntags.test -o /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/lld/test/ELF/linkerscript/Output/empty-relaplt-dyntags.test.tmp
# .---command stderr------------
# | terminate called after throwing an instance of 'std::system_error'
# |   what():  Resource temporarily unavailable
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
# | ld.lld: error: failed to write output '/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/lld/test/ELF/linkerscript/Output/empty-relaplt-dyntags.test.tmp': No such file or directory
# |  #0 0x00006248b7533fb0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/ld.lld+0x657fb0)
# |  #1 0x00006248b7530c6f llvm::sys::RunSignalHandlers() (/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/ld.lld+0x654c6f)
# |  #2 0x00006248b7530dc2 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
# |  #3 0x000078c31377c520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
# |  #4 0x000078c3137d09fc __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
# |  #5 0x000078c3137d09fc __pthread_kill_internal ./nptl/pthread_kill.c:78:10
# |  #6 0x000078c3137d09fc pthread_kill ./nptl/pthread_kill.c:89:10
# |  #7 0x000078c31377c476 gsignal ./signal/../sysdeps/posix/raise.c:27:6
# |  #8 0x000078c3137627f3 abort ./stdlib/abort.c:81:7
# |  #9 0x000078c313b0eb9e (/lib/x86_64-linux-gnu/libstdc++.so.6+0xa2b9e)
# | #10 0x000078c313b1a20c (/lib/x86_64-linux-gnu/libstdc++.so.6+0xae20c)
# | #11 0x000078c313b1a277 (/lib/x86_64-linux-gnu/libstdc++.so.6+0xae277)
# | #12 0x000078c313b1a4d8 (/lib/x86_64-linux-gnu/libstdc++.so.6+0xae4d8)
# | #13 0x000078c313b1183c std::__throw_system_error(int) (/lib/x86_64-linux-gnu/libstdc++.so.6+0xa583c)
# | #14 0x000078c313b4833d (/lib/x86_64-linux-gnu/libstdc++.so.6+0xdc33d)
# | #15 0x00006248baad569e std::thread::_State_impl<std::thread::_Invoker<std::tuple<llvm::parallel::detail::(anonymous namespace)::ThreadPoolExecutor::ThreadPoolExecutor(llvm::ThreadPoolStrategy)::'lambda'()>>>::_M_run() Parallel.cpp:0:0
# | #16 0x000078c313b48253 (/lib/x86_64-linux-gnu/libstdc++.so.6+0xdc253)
# | #17 0x000078c3137ceac3 start_thread ./nptl/pthread_create.c:442:8
# | #18 0x000078c313860850 ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:83:0
# `-----------------------------
# error: command failed with exit status: 250

--

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


```

</details>

https://github.com/llvm/llvm-project/pull/163542