Fuzz structural type canonicalization (#4510)
Fuzz structural type canonicalization (#4510)

Add a new fuzz checker to wasm-type-fuzzer that builds copies of the originally
built types, randomly selecting for each child type from all potential sources,
including both the originally built types and the not-yet-built duplicate types.
After building the new types, check that they are indeed identical to the old
types, which means that nothing has gone wrong with canonicalization.
WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen