[FIRRTL] Assertion failure on grand central when running with `-debug`

[uenoku]

// -----// IR Dump After AssignOutputDirs (firrtl-assign-output-dirs) //----- //
firrtl.circuit "test" {
  firrtl.module @test(in %clock: !firrtl.clock, in %reset: !firrtl.uint<1>, out %io_out: !firrtl.uint<6>) {
    %c1_ui6 = firrtl.constant 1 : !firrtl.uint<6>
    %reg = firrtl.reg %clock {firrtl.random_init_start = 0 : ui64} : !firrtl.clock, !firrtl.uint<6>
    %0 = firrtl.add %reg, %c1_ui6 : (!firrtl.uint<6>, !firrtl.uint<6>) -> !firrtl.uint<7>
    %1 = firrtl.bits %0 5 to 0 : (!firrtl.uint<7>) -> !firrtl.uint<6>
    firrtl.matchingconnect %reg, %1 : !firrtl.uint<6>
    firrtl.matchingconnect %io_out, %reg : !firrtl.uint<6>
  }
}

[firtool]   -- Done in 0.000 sec
[firtool]   Running "firrtl-grand-central{companion-mode=bind}"
===- Running GrandCentral ---------------------------------------------------===
Extraction Info:
  <none>
DUT: PLEASE submit a bug report to https://github.com/llvm/circt and include the crash backtrace.
Stack dump:
0.      Program arguments: ./build/bin/firtool bar.mlir -debug -verbose-pass-executions -mlir-print-ir-after-all
 #0 0x0000000000816ed7 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /scratch/hidetou/circt-synth/llvm/llvm/lib/Support/Unix/Signals.inc:804:13
 #1 0x0000000000814e10 llvm::sys::RunSignalHandlers() /scratch/hidetou/circt-synth/llvm/llvm/lib/Support/Signals.cpp:106:18
 #2 0x00000000008177ea SignalHandler(int, siginfo_t*, void*) /scratch/hidetou/circt-synth/llvm/llvm/lib/Support/Unix/Signals.inc:0:3
 #3 0x00007f727388fcf0 __restore_rt (/lib64/libpthread.so.0+0x12cf0)
 #4 0x0000000000d5a340 circt::firrtl::InstanceInfo::getDut() /scratch/hidetou/circt-synth/lib/Analysis/FIRRTLInstanceInfo.cpp:228:10
 #5 0x0000000000980504 (anonymous namespace)::GrandCentralPass::runOnOperation() /scratch/hidetou/circt-synth/lib/Dialect/FIRRTL/Transforms/GrandCentral.cpp:1894:3
 #6 0x00000000015e3119 mlir::detail::OpToOpPassAdaptor::run(mlir::Pass*, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int)::$_7::operator()() const /scratch/hidetou/circt-synth/llvm/mlir/lib/Pass/Pass.cpp:0:17
 #7 0x00000000015e3119 void llvm::function_ref<void ()>::callback_fn<mlir::detail::OpToOpPassAdaptor::run(mlir::Pass*, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int)::$_7>(long) /scratch/hidetou/circt-synth/llvm/llvm/include/llvm/ADT/STLFunctionalExtras.h:46:12
 #8 0x00000000015e3119 llvm::function_ref<void ()>::operator()() const /scratch/hidetou/circt-synth/llvm/llvm/include/llvm/ADT/STLFunctionalExtras.h:69:12
 #9 0x00000000015e3119 void mlir::MLIRContext::executeAction<mlir::PassExecutionAction, mlir::Pass&>(llvm::function_ref<void ()>, llvm::ArrayRef<mlir::IRUnit>, mlir::Pass&) /scratch/hidetou/circt-synth/llvm/mlir/include/mlir/IR/MLIRContext.h:280:7
#10 0x00000000015e3119 mlir::detail::OpToOpPassAdaptor::run(mlir::Pass*, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int) /scratch/hidetou/circt-synth/llvm/mlir/lib/Pass/Pass.cpp:522:21