[llvm] [NFC] LLVM reduce: remove unused variable (PR #133584)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lld-x86_64-ubuntu-fast` running on `as-builder-4` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/33/builds/13994

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
52.552 [5/26/3922] Generating ../../bin/llvm-dlltool
52.641 [5/25/3923] Linking CXX executable bin/sancov
52.691 [5/24/3924] Linking CXX executable bin/llvm-debuginfo-analyzer
52.698 [5/23/3925] Linking CXX executable bin/llvm-objdump
52.711 [4/23/3926] Generating ../../bin/llvm-otool
52.731 [4/22/3927] Linking CXX executable bin/llvm-nm
52.739 [4/21/3928] Linking CXX executable bin/llvm-libtool-darwin
52.756 [4/20/3929] Linking CXX executable bin/llvm-lipo
52.875 [4/19/3930] Linking CXX executable bin/llvm-cfi-verify
52.999 [4/18/3931] Building CXX object tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceOperandsToArgs.cpp.o
FAILED: tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceOperandsToArgs.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/c++ -DGTEST_HAS_RTTI=0 -DLLVM_BUILD_STATIC -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/tools/llvm-reduce -I/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/tools/llvm-reduce -I/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/include -I/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceOperandsToArgs.cpp.o -MF tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceOperandsToArgs.cpp.o.d -o tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceOperandsToArgs.cpp.o -c /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/tools/llvm-reduce/deltas/ReduceOperandsToArgs.cpp
/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/tools/llvm-reduce/deltas/ReduceOperandsToArgs.cpp: In function ‘void replaceFunctionCalls(llvm::Function*, llvm::Function*)’:
/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/tools/llvm-reduce/deltas/ReduceOperandsToArgs.cpp:112:29: error: ‘void llvm::FPMathOperator::setFastMathFlags(llvm::FastMathFlags)’ is private within this context
  112 |       FPOp->setFastMathFlags(CI->getFastMathFlags());
      |       ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/tools/llvm-reduce/deltas/ReduceOperandsToArgs.cpp:17:
/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/include/llvm/IR/Operator.h:264:8: note: declared private here
  264 |   void setFastMathFlags(FastMathFlags FMF) {
      |        ^~~~~~~~~~~~~~~~
53.160 [4/17/3932] Linking CXX executable bin/llvm-profgen
53.721 [4/16/3933] Linking CXX executable bin/llvm-jitlink
59.855 [4/15/3934] Linking CXX executable bin/llvm-gsymutil
60.035 [4/14/3935] Linking CXX executable bin/llvm-split
60.175 [4/13/3936] Linking CXX executable bin/llvm-dwp
60.201 [4/12/3937] Linking CXX executable bin/dsymutil
60.247 [4/11/3938] Linking CXX executable bin/llvm-c-test
60.329 [4/10/3939] Linking CXX executable bin/llvm-dwarfutil
60.421 [4/9/3940] Linking CXX executable bin/llvm-isel-fuzzer
60.624 [4/8/3941] Linking CXX executable bin/llvm-opt-fuzzer
61.059 [4/7/3942] Linking CXX executable bin/llvm-lto
61.089 [4/6/3943] Linking CXX executable bin/opt
61.215 [4/5/3944] Linking CXX shared library lib/libLTO.so.21.0git
61.264 [4/4/3945] Linking CXX executable bin/llvm-lto2
61.272 [4/3/3946] Linking CXX executable bin/bugpoint
61.318 [4/2/3947] Linking CXX executable bin/llc
61.814 [4/1/3948] Linking CXX executable bin/lld
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/133584