[llvm] [DAG] visitFREEZE - always allow freezing multiple operands (PR #145939)

[Jordan Rupprecht via llvm-commits]

rupprecht wrote:

Slightly more info while I reduce:

```
assert.h assertion failed at llvm/lib/CodeGen/MachineFunction.cpp:1135 in DebugInstrOperandPair llvm::MachineFunction::salvageCopySSAImpl(MachineInstr &): MRI.hasOneDef(State.first)
...
    @     0x55bcda950a24  __assert_fail
    @     0x55bcd8a2071a  llvm::MachineFunction::salvageCopySSAImpl()
    @     0x55bcd8a1fd0f  llvm::MachineFunction::salvageCopySSA()
    @     0x55bcd8a20a9f  llvm::MachineFunction::finalizeDebugInstrRefs()
    @     0x55bcd8e1ef94  llvm::SelectionDAGISel::runOnMachineFunction()
    @     0x55bcd8e1b8c9  llvm::SelectionDAGISelLegacy::runOnMachineFunction()
    @     0x55bcd8a26b26  llvm::MachineFunctionPass::runOnFunction()
    @     0x55bcda39fed8  llvm::FPPassManager::runOnFunction()
    @     0x55bcda3a7fdd  llvm::FPPassManager::runOnModule()
    @     0x55bcda3a0723  llvm::legacy::PassManagerImpl::run()
```

https://github.com/llvm/llvm-project/pull/145939