[Seq] Canonicalization Crash

I noticed the following crash when running on macOS locally using commit (0165281a2ffb027635bf2b32f824af11ec66a3f5). My guess is the LLVM bump (dc1d549552df0e1335e6770d93cf14120ece0a7c) exposed this.

# circt-opt -canonicalize ../test/Dialect/Seq/canonicalization.mlir 
PLEASE submit a bug report to https://github.com/llvm/circt and include the crash backtrace.
Stack dump:
0.  Program arguments: circt-opt -canonicalize ../test/Dialect/Seq/canonicalization.mlir
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  circt-opt                0x0000000100db9f6d llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 61
1  circt-opt                0x0000000100dba4db PrintStackTraceSignalHandler(void*) + 27
2  circt-opt                0x0000000100db8146 llvm::sys::RunSignalHandlers() + 134
3  circt-opt                0x0000000100dbb6bf SignalHandler(int) + 223
4  libsystem_platform.dylib 0x00007ff816baf5ed _sigtramp + 29
5  libsystem_platform.dylib 0x0100000100b33d03 _sigtramp + 71916894834673459
6  circt-opt                0x0000000103353529 mlir::Operation::getDiscardableAttrs() + 25
7  circt-opt                0x0000000103352d5e mlir::Operation::getAttrs() + 62
8  circt-opt                0x00000001023ed324 circt::seq::FirMemReadWriteOp::canonicalize(circt::seq::FirMemReadWriteOp, mlir::PatternRewriter&) + 356
9  circt-opt                0x0000000102426f3e mlir::RewritePatternSet& mlir::RewritePatternSet::add<circt::seq::FirMemReadWriteOp>(mlir::LogicalResult (*)(circt::seq::FirMemReadWriteOp, mlir::PatternRewriter&), mlir::PatternBenefit, llvm::ArrayRef<llvm::StringRef>)::FnPattern::matchAndRewrite(circt::seq::FirMemReadWriteOp, mlir::PatternRewriter&) const + 46

Edit: More likely this is just a bug in the Seq dialect FIRRTL mem op that was added in 956b581c68d0757615c601597f438dfd586d9b91.

llvm / circt

[Seq] Canonicalization Crash #5461