[llvm] [SandboxVec][Legality] Don't vectorize when instructions repeat (PR #124479)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-dylib` running on `linaro-flang-aarch64-dylib` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/50/builds/9597

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
445.439 [1038/1/5787] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIAsync.dir/Async.cpp.o
445.566 [1037/1/5788] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIAsync.dir/AsyncPasses.cpp.o
445.687 [1036/1/5789] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIControlFlow.dir/ControlFlow.cpp.o
445.832 [1035/1/5790] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIAMDGPU.dir/AMDGPU.cpp.o
445.982 [1034/1/5791] Linking CXX static library lib/libMLIRCAPIDebug.a
446.140 [1033/1/5792] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIMath.dir/Math.cpp.o
446.271 [1032/1/5793] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIEmitC.dir/EmitC.cpp.o
446.392 [1031/1/5794] Building CXX object tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestMatchers.cpp.o
446.528 [1030/1/5795] Building CXX object tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestLazyLoading.cpp.o
459.943 [1029/1/5796] Building CXX object tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestBytecodeRoundtrip.cpp.o
FAILED: tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestBytecodeRoundtrip.cpp.o 
/usr/local/bin/c++ -DGTEST_HAS_RTTI=0 -DMLIR_INCLUDE_TESTS -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/test/lib/IR -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/../Dialect/Test -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/test/lib/IR/../Dialect/Test -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wundef -Werror=mismatched-tags -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestBytecodeRoundtrip.cpp.o -MF tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestBytecodeRoundtrip.cpp.o.d -o tools/mlir/test/lib/IR/CMakeFiles/MLIRTestIR.dir/TestBytecodeRoundtrip.cpp.o -c /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/TestBytecodeRoundtrip.cpp
In file included from /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/TestBytecodeRoundtrip.cpp:10:
/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/IR/../Dialect/Test/TestOps.h:148:10: fatal error: 'TestOps.h.inc' file not found
  148 | #include "TestOps.h.inc"
      |          ^~~~~~~~~~~~~~~
1 error generated.
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/124479