reduce: segfault caused by StructuredLoopToSelectionReductionOpportunity querying dominance information for instructions that are not within blocks #2457
Description
Files to reproduce the problem
Running:
spirv-reduce to_reduce.spv ./interesting.py
leads to a spirv-reduce segfault.
The interestingness test depends on a spirv-opt/spirv-val bug, which is present in SPIRV-Tools revision 5186ffe
Found using GraphicsFuzz. I love how fuzzers and reducers fuzz themselves.