Rework the switch module in cranelift-frontend in terms of brif (#5644)

Rework the compilation strategy for switch to:
* use brif instead of brz and brnz
* generate tables inline, rather than delyaing them to after the decision tree has been generated
* avoid allocating new vectors by using slices into the sorted contiguous ranges
* avoid generating some unconditional jumps
* output differences in test output using the similar crate for easier debugging

cranelift/frontend/Cargo.toml

@@ -17,6 +17,9 @@ log = { workspace = true }
 hashbrown = { workspace = true, optional = true }
 smallvec = { workspace = true }
 
+[dev-dependencies]
+similar = { workspace = true }
+
 [features]
 default = ["std"]
 std = ["cranelift-codegen/std"]