[mlir][affine](affine-loop-fusion) mlir-opt crash at Affine/Analysis/Utils.cpp:256

git version: 7ece48b9e5bb7aafdcc53aa2445328a67b501d24

MLIR Program:
```mlir
module {
func.func @m() {
%alloc = memref.alloc() : memref<10xf32>
%alloc_1 = memref.alloc() : memref<10xf32>
affine.for %arg0 = 0 to 10 step 128 {
%1 = ub.poison : f32
%2 = vector.transfer_read %alloc_1[%arg0], %1 : memref<10xf32>, vector<128xf32>
vector.transfer_write %2, %alloc[%arg0] : vector<128xf32>, memref<10xf32>
}
affine.for %arg0 = 0 to 10 step 128 {
%1 = ub.poison : f32
%2 = vector.transfer_read %alloc[%arg0], %1 : memref<10xf32>, vector<128xf32>
}
return
}
}
```

Reproduce Command: `mlir-opt --affine-loop-fusion a.mlir`

StackTrace:
```
unexpected op
UNREACHABLE executed at /data2/dependency/dev/llvm-project/mlir/lib/Dialect/Affine/Analysis/Utils.cpp:256!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0. Program arguments: mlir-opt --affine-loop-fusion a.mlir
#0 0x000055fc26735ddf llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x20bfddf)
#1 0x000055fc2673294c llvm::sys::RunSignalHandlers() (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x20bc94c)
#2 0x000055fc26732af3 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#3 0x00007f6c6f92b420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
#4 0x00007f6c6f41600b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
#5 0x00007f6c6f3f5859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
#6 0x000055fc2671336e (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x209d36e)
#7 0x000055fc2e30dea8 getMemRef(mlir::Operation*) Utils.cpp:0:0
#8 0x000055fc2e30e134 mayDependence(mlir::affine::MemRefDependenceGraph::Node const&, mlir::affine::MemRefDependenceGraph::Node const&, mlir::Value)::'lambda'(llvm::ArrayRef, llvm::ArrayRef)::operator()(llvm::ArrayRef, llvm::ArrayRef) const::'lambda'(mlir::Operation*)::operator()(mlir::Operation*) const (.isra.0) Utils.cpp:0:0
#9 0x000055fc2e30e41c mlir::Operation* const* std::__find_if, llvm::ArrayRef)::operator()(llvm::ArrayRef, llvm::ArrayRef) const::'lambda'(mlir::Operation*)>>(mlir::Operation* const*, mlir::Operation* const*, __gnu_cxx::__ops::_Iter_pred, llvm::ArrayRef)::operator()(llvm::ArrayRef, llvm::ArrayRef) const::'lambda'(mlir::Operation*)>, std::random_access_iterator_tag) (.isra.0) Utils.cpp:0:0
#10 0x000055fc2e3202d8 mlir::affine::MemRefDependenceGraph::init(bool) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x9caa2d8)
#11 0x000055fc2e0092b5 (anonymous namespace)::LoopFusion::runOnBlock(mlir::Block*) LoopFusion.cpp:0:0
#12 0x000055fc2e009f61 void llvm::function_ref::callback_fn<(anonymous namespace)::LoopFusion::runOnOperation()::'lambda'(mlir::Operation*)>(long, mlir::Operation*) LoopFusion.cpp:0:0
#13 0x000055fc2e009c21 (anonymous namespace)::LoopFusion::runOnOperation() LoopFusion.cpp:0:0
#14 0x000055fc2fca1581 mlir::detail::OpToOpPassAdaptor::run(mlir::Pass*, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0xb62b581)
#15 0x000055fc2fca1910 mlir::detail::OpToOpPassAdaptor::runPipeline(mlir::OpPassManager&, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int, mlir::PassInstrumentor*, mlir::PassInstrumentation::PipelineParentInfo const*) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0xb62b910)
#16 0x000055fc2fca39c4 mlir::PassManager::runPasses(mlir::Operation*, mlir::AnalysisManager) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0xb62d9c4)
#17 0x000055fc2fca4a41 mlir::PassManager::run(mlir::Operation*) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0xb62ea41)
#18 0x000055fc267fc17b performActions(llvm::raw_ostream&, std::shared_ptr const&, mlir::MLIRContext*, mlir::MlirOptMainConfig const&) MlirOptMain.cpp:0:0
#19 0x000055fc267fccbf processBuffer(llvm::raw_ostream&, std::unique_ptr>, llvm::MemoryBufferRef, mlir::MlirOptMainConfig const&, mlir::DialectRegistry&, mlir::SourceMgrDiagnosticVerifierHandler*, llvm::ThreadPoolInterface*) MlirOptMain.cpp:0:0
#20 0x000055fc267fceeb llvm::LogicalResult llvm::function_ref>, llvm::MemoryBufferRef const&, llvm::raw_ostream&)>::callback_fn>, mlir::DialectRegistry&, mlir::MlirOptMainConfig const&)::'lambda'(std::unique_ptr>, llvm::MemoryBufferRef, llvm::raw_ostream&)>(long, std::unique_ptr>, llvm::MemoryBufferRef const&, llvm::raw_ostream&) MlirOptMain.cpp:0:0
#21 0x000055fc300862b5 mlir::splitAndProcessBuffer(std::unique_ptr>, llvm::function_ref>, llvm::MemoryBufferRef const&, llvm::raw_ostream&)>, llvm::raw_ostream&, llvm::StringRef, llvm::StringRef) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0xba102b5)
#22 0x000055fc267f2f34 mlir::MlirOptMain(llvm::raw_ostream&, std::unique_ptr>, mlir::DialectRegistry&, mlir::MlirOptMainConfig const&) (.part.0) MlirOptMain.cpp:0:0
#23 0x000055fc267fd407 mlir::MlirOptMain(int, char**, llvm::StringRef, llvm::StringRef, mlir::DialectRegistry&) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x2187407)
#24 0x000055fc267fd643 mlir::MlirOptMain(int, char**, llvm::StringRef, mlir::DialectRegistry&) (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x2187643)
#25 0x000055fc2669ca97 main (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x2026a97)
#26 0x00007f6c6f3f7083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#27 0x000055fc2671277e _start (/data2/dependency/dev/llvm-project/build/bin/mlir-opt+0x209c77e)
Aborted (core dumped)
```

Reproduce the crash with mlir-opt --affine-loop-fusion a.mlir using the MLIR program in the issue. Start at mlir/lib/Dialect/Affine/Analysis/Utils.cpp:256, then trace the callers through LoopFusion.cpp. Done means this input no longer aborts and regression coverage verifies the corrected behavior.

Written by the indexing model from the issue text.