Compiler segfaults while emitting verilog with cryptic error message

**Describe the bug**

When trying to generate Verilog for a fairly complex module written in DSLX the compiler segfaults.

**To Reproduce**
Steps to reproduce the behavior:

- Follow the XLS setup instructions for Ubuntu 2024
- Git clone my [XLS fork](https://github.com/joonho3020/xls/tree/joonho-main)
- Run `bazel build --verbose_failures -- //xls/modules/snappy:snappy_decompressor_verilog`

**Expected behavior**
A clear and concise description of what you expected to happen.

I expect to see the generated verilog

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Environment (this can be helpful for troubleshooting):**
- OS: [e.g. Ubuntu]
- Versions [e.g. 22.04]

**Additional context**
Add any other context about the problem here.