[NewGVN] Assertion `BeforeCC->isEquivalentTo(AfterCC) && "Value number changed after main loop completed!"' failed.

Reproducer:
https://godbolt.org/z/6hjfex44e

Backtrace:
```console
opt: /root/llvm-project/llvm/lib/Transforms/Scalar/NewGVN.cpp:3318: void {anonymous}::NewGVN::verifyIterationSettled(llvm::Function&): Assertion `BeforeCC->isEquivalentTo(AfterCC) && "Value number changed after main loop completed!"' failed.
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: /opt/compiler-explorer/clang-assertions-trunk/bin/opt -o /app/output.s -S -passes=simplifycfg,loop-unroll,newgvn
1. Running pass "function(simplifycfg,loop-unroll,newgvn)" on module ""
2. Running pass "newgvn" on function "loop3"
#0 0x00000000008ff848 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x8ff848)
#1 0x00000000008fc634 llvm::sys::RunSignalHandlers() (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x8fc634)
#2 0x00000000008fc7ae SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#3 0x0000710ca8645330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#4 0x0000710ca869ec0c pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x9ec0c)
#5 0x0000710ca864527e raise (/lib/x86_64-linux-gnu/libc.so.6+0x4527e)
#6 0x0000710ca86288ff abort (/lib/x86_64-linux-gnu/libc.so.6+0x288ff)
#7 0x0000710ca862881b (/lib/x86_64-linux-gnu/libc.so.6+0x2881b)
#8 0x0000710ca863b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
#9 0x0000000004b3265b (anonymous namespace)::NewGVN::verifyIterationSettled(llvm::Function&) (.isra.0) NewGVN.cpp:0:0
#10 0x0000000004b33a99 (anonymous namespace)::NewGVN::runGVN() NewGVN.cpp:0:0
#11 0x0000000004b3564e llvm::NewGVNPass::run(llvm::Function&, llvm::AnalysisManager&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4b3564e)
#12 0x00000000031c48fe llvm::detail::PassModel>::runImpl(llvm::detail::PassConcept>&, llvm::Function&, llvm::AnalysisManager&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x31c48fe)
#13 0x0000000005ae9921 llvm::PassManager>::run(llvm::Function&, llvm::AnalysisManager&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5ae9921)
#14 0x0000000000fc936e llvm::detail::PassModel>, llvm::AnalysisManager>::runImpl(llvm::detail::PassConcept>&, llvm::Function&, llvm::AnalysisManager&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0xfc936e)
#15 0x0000000005ae82ec llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5ae82ec)
#16 0x00000000009be94e llvm::detail::PassModel>::runImpl(llvm::detail::PassConcept>&, llvm::Module&, llvm::AnalysisManager&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x9be94e)
#17 0x0000000005ae7ade llvm::PassManager>::run(llvm::Module&, llvm::AnalysisManager&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5ae7ade)
#18 0x00000000009c842a llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef, llvm::ArrayRef>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x9c842a)
#19 0x00000000009bca4b optMain (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x9bca4b)
#20 0x0000000000835a10 main (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x835a10)
#21 0x0000710ca862a1ca (/lib/x86_64-linux-gnu/libc.so.6+0x2a1ca)
#22 0x0000710ca862a28b __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2a28b)
#23 0x00000000008de6b5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x8de6b5)
Program terminated with signal SIGABRT (6)
Compiler returned: 134
```

This comes from llvm/test/Analysis/MemorySSA/invariant-groups.ll

Start with the reproducer and the pass pipeline shown in the issue, then inspect llvm/lib/Transforms/Scalar/NewGVN.cpp around verifyIterationSettled. Review llvm/test/Analysis/MemorySSA/invariant-groups.ll and run the relevant opt pipeline. Done means the assertion no longer occurs and the regression remains covered by the test.

Written by the indexing model from the issue text.