* cranelift-filetest: Add the ability to test `.wat` to assembly
* Make the load/store test case generator script use `.wat` tests
And generate tests that exercise both Wasm-to-CLIF lowering and Wasm all the way
to assembly.
* Remove old versions of generated load/store tests
* Add new generated load/store tests
* Fix filename reference in script
* clif-util: do not convert `anyhow::Error`s into strings into `anyhow::Error`s
* filetests: Use the debug formatting of `anyhow::Error`s
This provides the full error context, not just the source error's message.
